An electrical parameter measurement device and a method of operating an electrical parameter measurement device

Abstract

This invention is entitled a non-contact electrical parameter measurement device with radially dual mounted sensors. Systems and methods for operating and calibrating the electrical parameter measurement device are provided herein. The device may include a current sensor comprising a plurality of magnetic field sensors positioned around a measurement region receiving a current-carrying conductor under test. The sensor may include a plurality of concentric loops of magnetic field sensors that provide accurate measurements ignoring conductors or other components outside the measurement region. The sensors can be used to determine the position of the conductor under test, and such information can be used to generate accurate measurements by taking the position of the conductor into account. A calibration system may also be provided, which operates to generate calibration data, which is subsequently used to provide more accurate measurements. The calibration data may include one or more lookup tables, coefficients for one or more mathematical formulas, or other types of data.

Description

Technical Field

[0001] This disclosure generally relates to electrical parameter measuring devices, and more specifically to non-contact electrical parameter measuring devices. Prior Technology

[0002] Related technical descriptions A voltmeter is an instrument used to measure voltage in a circuit. An instrument that measures more than one electrical characteristic is called a multimeter, and it is operated to measure many parameters typically needed for troubleshooting, servicing, and maintenance applications. These parameters typically include alternating current (AC) voltage and current, direct current (DC) voltage and current, and resistance or continuity. Other parameters, such as power characteristics, frequency, capacitance, and temperature, can also be measured to meet the requirements of specific applications. For conventional voltmeters or multimeters used to measure AC voltage, at least two measuring electrodes or probes need to be in contact with the conductor current. This typically requires cutting a portion of the insulation from the insulated wire or providing the measuring terminals beforehand. Besides requiring exposed wire or terminals for current contact, the step of touching the voltmeter probe to the stripped wire or terminals can be quite dangerous due to the risk of electric shock. “Non-contact” voltage measuring devices can be used to detect the presence of alternating current (AC) voltage without requiring current contact with the circuit. When voltage is detected, the user is alerted by indicators such as lights, buzzers, or vibrating motors. However, such non-contact voltage detectors only provide an indication of the presence or absence of AC voltage and do not provide an indication of the actual magnitude of the AC voltage (e.g., RMS value). For example, because multimeters test the current carrying capacity of leads and circuits, general-purpose multimeters with internal shunts can be limited to a maximum of ten amps. Furthermore, multimeters typically require internal fuses for protection against excessive current levels flowing through them, both for safety reasons and to prevent damage. Removing blown fuses is difficult, and purchasing replacement fuses requires time and cost, making non-contact current measuring instruments that do not require internal fuses desirable. Clamp-on multimeters offer a superior ability to measure current compared to general-purpose multimeters by employing an integrated current clamp that senses the current in a current-carrying conductor without having to disconnect the conductor or the circuitry containing it. The current clamp is typically provided in the same housing as the multimeter, which uses separate test probes to measure other parameters such as voltage and resistance in a conventional manner. The current clamp closes around the current-carrying conductor to sense the magnetic field generated by the current. The current clamp provides a voltage signal to the multimeter's measurement, which calculates and displays the measured current level. Because no current is shunt from the current-carrying conductor through the clamp-on multimeter, the limitation on the maximum measurable current is largely eliminated. Similarly, the internal fuse in a clamp-on multimeter is eliminated. To obtain an effective current measurement, the magnetic core in the current clamp must be wrapped around the current-carrying conductor to close the clamp. The current clamp must be mechanically actuated to open the jaws, insert the current-carrying conductor, and then close the jaws around it. The jaws must be aligned to complete the magnetic core for an effective current measurement. Because of the large amount of iron used in the magnetic core, clamp multimeters are physically heavy. Furthermore, high-level currents can saturate the magnetic core. Therefore, the current measurement capacity of a clamp multimeter is limited to current levels that do not saturate the magnetic core. In addition, the performance in terms of frequency bandwidth and phase angle is also limited, depending on the magnetic material. In addition, other methods of measuring magnetic field / magnetic flux, such as the Rogowski coil, have other drawbacks, such as the inability to measure DC current and the need for an integrator to recover the original current waveform and magnitude. Furthermore, for some electrical parameter measuring devices, such as current clamps or split-core transformers, the conductor under test can be freely positioned at various physical locations within the front end of the measuring device or the probe tip. In some cases, the variable position of the conductor under test can adversely affect the measurement of one or more electrical parameters (e.g., voltage, current, power), leading to inaccurate measurement results. Therefore, it is advantageous to determine the position of the conductor under test and / or compensate for the determined position when performing measurements of one or more electrical parameters. Summary of the Invention

[0003] An electrical parameter measuring device can be broadly categorized as follows: a front end including an opening sized and dimensionally designed to receive a conductor under test; a plurality of magnetic field sensors disposed around the opening on a support member, the plurality of magnetic field sensors comprising: a first set of equally spaced magnetic field sensors positioned at a first radial distance from the center of the opening, and a second set of equally spaced magnetic field sensors positioned at a second radial distance from the center of the opening, the second radial distance being greater than the first radial distance, and each magnetic field sensor in the first set being radially aligned with a corresponding magnetic field sensor in the second set; and control circuitry operatively coupled to the plurality of magnetic field sensors, the control circuitry being configured to: receive at least one sensor signal from the plurality of magnetic field sensors; determine the physical position of the conductor under test based at least in part on the received at least one sensor signal; and determine a current parameter of the conductor based at least in part on the received at least one sensor signal and the determined physical position. The current parameter may include alternating current (AC) or direct current (DC). Each of the plurality of magnetic field sensors may include at least one of the following: anisotropic magnetoresistive (AMR) sensor, giant magnetoresistive (GMR) sensor, Hall effect sensor, fluxgate sensor, or coil. Control circuitry may be configured to determine the physical position of the conductor under test using sensor signals from exactly two of the magnetic field sensors. At least one of the plurality of magnetic field sensors may include a first sub-sensor and a second sub-sensor arranged at a 90-degree angle relative to the first sub-sensor. Each of the plurality of magnetic field sensors may be formed in an integrated circuit including at least one of the other magnetic field sensors. Each magnetic field sensor in a first group may be formed in the integrated circuit together with its corresponding radially aligned magnetic field sensor in a second group. Each magnetic field sensor in the first group may be coupled in series with each other, and each magnetic field sensor in the second group may be coupled in series with each other. Each magnetic field sensor may be individually coupled to control circuitry. Multiple magnetic field sensors may include a third set of equally spaced magnetic field sensors positioned at a third radial distance from the center of the opening, the third radial distance being greater than the second radial distance, and control circuitry operable to: determine that at least one magnetic field sensor in the first set of magnetic field sensors is saturated due to the amount of current in the conductor under test; and determine the current parameters of the conductor based at least in part on sensor signals from the second and third sets of magnetic field sensors. To determine the current parameters of the conductor, the control circuitry may be configured to apply a calibration factor dependent on a determined physical location of the conductor under test. The control circuitry may be configured to determine that at least one magnetic field sensor is saturated and ignore the sensor signal from that at least one magnetic field sensor to determine the current parameters of the conductor under test. The control circuitry may be configured to determine that at least one magnetic field sensor is saturated and, in response to this determination, replace the sensor signal of the saturated magnetic field sensor with an interpolated sensor signal obtained using sensor signals from a magnetic field sensor positioned adjacent to the saturated magnetic field sensor. The electrical parameter measuring device may also include a plurality of non-contact voltage sensors operatively coupled to control circuitry, wherein the control circuitry determines the physical location of the conductor under test based at least in part on sensor signals received from the plurality of non-contact voltage sensors. The control circuitry may be configured to determine the voltage parameters of the conductor under test based at least in part on sensor signals received from the plurality of non-contact voltage sensors. Each of the plurality of magnetic field sensors is operable to determine the direction of the magnetic field generated by the conductor under test. The control circuitry may apply a unique calibration factor to each of the plurality of magnetic field sensors. Simple Explanation of the Diagram

[0004] In the accompanying drawings, the same reference numerals identify similar elements or actions. The size and relative position of the elements in the drawings are not necessarily drawn to scale. For example, the shapes and angles of various elements are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve the readability of the drawings. Furthermore, the particular shape of an element drawn may not necessarily convey any information about the actual shape of that particular element and may be chosen solely for ease of identification in the drawings. Additionally, the number of individual elements arranged in a ring in some drawings, for example, is an example and depends on the accuracy required for a specific application. [Figure 1] is a schematic diagram of an electrical parameter measuring device that uses a magnetic sensor to measure AC or DC current according to a non-limiting illustrative embodiment. [Figure 2] is a block diagram showing the various front-end components of the electrical parameter measuring device of Figure 1. [Figure 3] is a drawing view of the front end or probe portion of an electrical parameter measuring device, showing an exemplary sensor arrangement of the device. [Figure 4] is a schematic diagram showing the physical arrangement of multiple magnetic sensors in an electrical parameter measuring device. [Figure 5A] is a perspective view of an electrical parameter measuring device including a dual magnetic radial sensor according to a non-limiting illustrative embodiment. [Figure 5B] is an enlarged view of a portion of the electrical parameter measuring device of Figure 5A, showing two radially spaced magnetic sensors of the electrical parameter measuring device. [Figure 6] is a schematic diagram showing an exemplary integrated dual sensor of an electrical parameter measurement device. [Figure 7] is a schematic diagram of an exemplary integrated dual sensor of an electrical parameter measuring device, which includes a sensor rotated 90 degrees to enable determination of the position of the conductor under test within the measurement area of ​​the electrical parameter measuring device. [Figure 8] is a schematic diagram showing the use of two sensor pairs in an electrical parameter measuring device to determine the position of the conductor under test within the measurement area. [Figure 9] is a drawing of the front end of an electrical parameter measuring device according to a non-limiting illustrative embodiment, showing the positions of multiple sensors that can be used to determine the position of the conductor under test or to determine one or more calibration factors for improving measurement accuracy. [Figure 10] is a drawing of an electrical parameter measuring device according to a non-limiting illustrative embodiment, which includes a plurality of independent sensors, each calibrated and measured independently of other sensors. [Figure 11A] is a drawing of an environment according to an exemplary embodiment in which an operator can use a non-contact voltage measuring device including a reference signal type voltage sensor to measure the AC voltage present in an insulated wire without having to come into contact with the current in the wire. [Figure 11B] is a top view of the non-contact voltage measuring device of Figure 11A according to an exemplary embodiment, showing the coupling capacitance formed between the insulated wire and the conductive sensor of the non-contact voltage measuring device, the current component of the insulated conductor, and the volume capacitance between the non-contact voltage measuring device and the operator. [Figure 12] is a schematic diagram of the various internal components of a non-contact voltage measuring device according to an exemplary embodiment. [Figure 13] is a block diagram illustrating various signal processing components of a non-contact voltage measuring device according to an exemplary embodiment. [Figure 14] is a schematic diagram of a non-contact voltage measurement device that implements Fast Fourier Transform (FFT) according to an exemplary embodiment. [Figure 15] is a schematic block diagram of a calibration system for an electrical parameter measuring device (such as the voltage measuring device shown in Figures 11A to 14) according to an exemplary embodiment. [Figure 16] is a schematic diagram of the V-shaped front end of an electrical parameter measuring device according to a non-limiting illustrative embodiment, showing three conductivity sensors that can be used to determine the position of the conductor under test. [Figure 17] is a schematic diagram of the V-shaped front end of an electrical parameter measuring device according to a non-limiting illustrative embodiment, showing two conductivity sensors that can be used to determine the position of the conductor under test, wherein the position of the two conductivity sensors allows for precise determination of the position of the conductor under test. [Figure 18] is a schematic diagram of the V-shaped front end of an electrical parameter measuring device according to a non-limiting illustrative embodiment, showing two conductivity sensors that can be used to determine the position of a conductor under test, wherein the position of the two conductivity sensors may lead to an inaccurate determination of the position of the conductor under test. [Figure 19] is a schematic diagram of the front end of an electrical parameter measuring device according to a non-limiting illustrative embodiment, showing two conductive sensors that are coplanar with each other and can be used to determine the position of the conductor under test. [Figure 20] is a schematic diagram of the V-shaped front end of an electrical parameter measuring device including three conductivity sensors according to a non-limiting illustrative embodiment, showing various possible positions of the conductor under test to determine the calibration factor for each position derived by triangulation through three reference currents (Iref1, Iref2, Iref3). [Figure 21] is a table showing the position-related calibration factors of three conductive sensors at various locations according to a non-limiting illustrative embodiment. [Figure 22] is a table showing the position-related calibration factors of a single conductivity sensor when the conductor under test is positioned at various distances from the conductivity sensor, according to a non-limiting illustrative embodiment. [Figure 23] is a graph according to a non-limiting illustrative embodiment, which shows the reference current signal and calibration factor of the conductive sensor as a function of distance. [Figure 24] is a graph according to a non-limiting illustrative embodiment, which shows a linear approximation of the reciprocal of the reference current signal as a function of distance and a polynomial approximation of the calibration factor. [Figure 25] is a graph according to a non-limiting illustrative embodiment, which shows the calibration factor as a function of the reciprocal of the reference current signal detected by the conductivity sensor. [Figure 26A] is a side front view of a portion of the front end of an electrical parameter measuring device according to a non-limiting illustrative embodiment, showing a V-shaped protective member supporting two conductive sensors. [Figure 26B] is a perspective view of a portion of the front end of the electrical parameter measuring device shown in Figure 26A. [Figure 27] is a graph according to a non-limiting illustrative embodiment, which shows a schematic representation of the two-dimensional normal distance correlation of the calibration factor of one of the sensors in the front end shown in Figures 26A and 26B. [Figure 28] is a graph according to a non-limiting illustrative embodiment, which shows the reference current signals and calibration factors of the two conductive sensors at the front end shown in Figures 26A and 26B as a function of normal distance. [Figure 29] is a schematic diagram according to a non-limiting illustrative embodiment, which shows the use of the normal distance emanating from a reference current signal to determine the position of the conductor under test. [Figure 30] is a drawing of the front end of a clamp meter according to a non-limiting illustrative embodiment, showing the positions of three conductivity sensors that can be used to determine the position of the conductor under test and / or to determine one or more calibration factors for improving measurement accuracy. [Figure 31] is a drawing of the front end of a clamp meter according to a non-limiting illustrative embodiment, showing the positions of three conductivity sensors that can be used to determine the position of the conductor under test and / or to determine one or more calibration factors for improving measurement accuracy, and showing three exemplary conductors with different diameters. [Figure 32] shows a three-dimensional graphical view of the sensor signal that can be used in the "optimal point" determination algorithm of this disclosure. [Figure 33] shows a graph of the calibration factor (Y-axis) of the reference current range (X-axis) of multiple sensors of a non-contact measuring device according to a non-limiting illustrative embodiment. [Figure 34] shows a graph of the calibration factor (Y-axis) of a sensor for a non-contact measuring device with reference current ranges (X-axis) for wires of various diameters. [Figure 35] shows a graph according to a non-limiting example of an implementation, which illustrates the calculation of the shortest distance from the test wire to the calibration wire segment. [Figure 36] shows multiple views of the optimal point region and the region outside the optimal point region for multiple test conductors with different diameters, according to a non-limiting illustrative embodiment. [Figure 37] is a table showing the outputs at various x / y positions of the conductor under test according to a non-limiting illustrative embodiment, which can be used to determine which of a variety of calibration methods is used for the conductor under test. [Figure 38] is a schematic diagram of the sensor clamping element input circuit, which includes a transimpedance amplifier and a current integrator to measure the voltage and current in the conductor under test, respectively. [Figure 39] shows a graph illustrating the correlation between the correction factor k and the characteristics of the reference current signal. [Figure 40] shows a graph according to a non-limiting example of an implementation, which illustrates the relative error introduced after RMS summation of the normalized fast Fourier transform window associated with the single correction factor method. Implementation

[0005] The systems and methods disclosed herein relate to electrical parameter measuring devices that utilize magnetic sensors to measure AC and / or DC currents in a conductor without requiring current contact between the measuring device and the conductor under test. The systems and methods of this disclosure also advantageously provide calibration of electrical parameter measuring devices (such as contact and non-contact "reference signal" type measuring devices, clamp meters, and split-core transformers), as well as conductor location determination for such devices and other devices. First, referring to Figures 1 through 10, electrical parameter measuring devices utilizing radially mounted sensors are discussed. Then, referring to Figures 11A through 14, various examples of reference signal type measuring devices are discussed. Furthermore, referring to Figures 15 through 30, various calibration systems and associated devices and methods are discussed. Various embodiments and features of this disclosure can be combined in any suitable manner to provide electrical parameter measuring devices for a variety of applications. In at least some embodiments, the calibration systems and methods disclosed herein can be used to calibrate non-contact measuring devices, wherein the measurement of one or more alternating current (AC) parameters in an insulated wire is performed without requiring a current connection between the insulated wire and the test electrode or probe. The calibration systems and methods can also be used to calibrate conventional contact measuring devices that generate and detect reference signals and utilize conductive test leads or probes in contact with the current of the conductor under test. Non-limiting examples of measuring devices that can be used with the embodiments discussed herein include digital multimeters, current clamps, and split-core transformers. In the following description, certain specific details are set forth in order to provide a thorough understanding of the various embodiments disclosed. However, those skilled in the art will recognize that these embodiments can be implemented without one or more of these specific details, or using other methods, components, materials, etc. In other instances, well-known structures associated with computer systems, server computers, and / or communication networks have not been shown or described in detail to avoid unnecessarily obscuring the description of these embodiments. Unless the context otherwise requires, throughout the specification and claims, the word “comprising” is synonymous with “including” and is inclusive or open-ended (i.e., does not exclude additional, unreferenced elements or method actions). Throughout this specification, references to "one embodiment" or "implementation" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, in one or more embodiments, a particular feature, structure, or characteristic may be combined in any suitable manner. As used in this specification and the appended claims, the singular forms “a” and “the” include the plural referents unless the context clearly indicates otherwise. It should also be noted that the term “or” is generally used to include “and / or” in its sense unless the context clearly indicates otherwise. The titles and descriptions provided herein are for convenience only and do not explain the scope or meaning of the embodiments. Radial dual-mount multi-sensor electrical parameter measurement equipment Figure 1 shows a circuit diagram of an electrical parameter measuring device 100 that operates to measure the current in a conductor 102 under test. In the illustrated embodiment, the device 100 includes 16 substantially identical sensors 104a to 104h (“sensors 104”) and sensors 106a to 106h (“sensors 106”) mounted on a support member 108 (such as a circuit board) of an electrically insulating material. The sensors 104 are mounted on the support member 108 at substantially equal intervals around a first circle of diameter D1 and are connected in series via non-magnetic conductors 110 (e.g., wires, circuit board traces). Similarly, the sensors 106 are mounted on the support member 108 at substantially equal intervals around a second circle of diameter D2 and are connected in series via a second conductor 112. The second circle is larger than the first circle and is substantially concentric with the first circle. In at least some embodiments, the magnetic axis of each sensor in sensors 104, 106 is tangent to its corresponding circle, and each sensor 104 is substantially radially aligned with its corresponding counterpart in sensors 106, i.e., the sensors are radially aligned in pairs: 104a / 106a, 104b / 106b, 104c / 106c, etc. That is, each pair includes sensors 104 arranged linearly with the corresponding sensor 106 in the radial direction. In the illustrated example, since there are eight equally spaced sensors in each sensor ring, each sensor in the ring is spaced 45 degrees apart. In other embodiments, depending on the number of sensors, the sensors in the ring may be spaced at different angles (e.g., 90 degrees for 4 sensors in the ring, 60 degrees for 6 sensors in the ring, and 30 degrees for 12 sensors in the ring). In at least some embodiments, such as the embodiment of FIG. 3 discussed below, the support member 108 may include a slot extending from its periphery beyond a point in the central region 114. Such a slot allows the conductor 102 under test to be introduced into the central region 114, wherein the axis of the conductor is orthogonal to the plane containing sensors 104 and 106 (i.e., orthogonal to the plane of FIG. 1). Depending on the sensor technology, the device 100 of Figure 1 is operable to measure AC and DC currents, with minimal influence from the position of the conductor 102 under test and minimal influence from external current sources outside the measurement area or central region 114. This is achieved by symmetrically arranging a pair of sensors 104, 106 that measure the magnetic field generated by the conductor 102 at defined symmetrical positions (e.g., angles and distances from the central region 114). Device 100 utilizes dual compensation, as discussed further below. Sensors 104, 106 can be any of a variety of magnetic sensing devices, including distributed coils, planar magnetic sensors (e.g., PCA coils), Hall effect sensors, flux gate sensors, anisotropic magnetoresistive (AMR) sensors (as shown), or any other suitable type of sensor. As described above, sensors 104 are operablely coupled in series with each other such that their output voltages are added together. Similarly, sensors 106 are operablely coupled in series with each other. The factor λ used to subtract the internal-external voltage can be determined according to the following equation (1), depending on the relative distance between the inner and outer circles: This technology can be used with any magnetic sensor, including distributed “air coils,” as discussed further below. The advantage of this magnetic field sensing technology is that the measurement is performed non-invasively, and the sensor suppresses interference from other external fields injected from adjacent conductors outside the sensor. Furthermore, this measurement method offers significantly lower cost and higher performance / accuracy levels compared to other conventional measurement solutions. For example, in at least some of the embodiments discussed herein, a “magnetic concentrator” such as an iron core is not required. To provide accurate measurements, for a given magnetic field in the central wire, the output signals from each sensor 104, 106 should be identical. This can be achieved by individually calibrating each of the sensors 104, 106 or by calibrating each group of sensors together. The output value of each sensor is affected by the wire position. The summed output voltage partially compensates for / reduces this positional effect, depending on the number of sensors. For external parasitic stray current sources, the ratio of the summed output voltages in each loop of sensors 104 and 106 is almost constant, regardless of the magnitude or location of the external source. This ratio can be expressed as Vexternal / Vinternal. Therefore, if, for example, the correct proportion of the output voltage Vexternal in the external loop is subtracted from the voltage Vinternal in the internal loop by choosing λ = Vexternal / Vinternal, the external field effect is canceled, meaning Vtotal = 0. To measure the current in the conductor 102 under test, the optimized sensor design provides λ / 2 Voutside / Vinside, regardless of the position of conductor 102. Therefore, the available signal for measurement is approximately Vtotal = Vinside / 2, resulting in approximately half of the signal collected by a concentric chain of sensors 104, 106 being used for measurement. Thus, this arrangement allows for the cancellation of signals caused by external current sources and utilizes approximately 50% of the potentially available signal for measurement. The more sensors used, the greater the suppression of external currents achieved. Device 100 includes a differential amplifier circuit 116 operable to subtract an external voltage Vexternal from an internal voltage Vinternal. The total output voltage Vtotal is obtained by applying the voltages Vexternal and Vinternal together through resistors R1 and R2, respectively, to the inverting input of the differential amplifier circuit 116, which has a feedback resistor Rgain. Optionally, a capacitor may also be placed in parallel with the feedback resistor Rgain to remove the frequency dependence of the input voltage. At the output of amplifier circuit 116, the ratio of the external voltage Vexternal subtracted from the internal voltage Vinternal is proportional to the ratio of the resistor values ​​R2 / R1, such that a desired value for Vtotal can be obtained by appropriately selecting R1 and R2. In at least some embodiments, the value of R2 is equal to R1 × λ. Figure 2 shows a block diagram 200 of the components of the circuitry including the sensor or probe of device 100. As shown, an external input voltage V is subtracted from the internal input voltage V by an adder / integrator 202, which may be similar to or the same as the amplifier circuit 116 of Figure 1. The resulting signal 204 is proportional to the current of the conductor 102 under test. Signal 204 is provided to a gain adjustment circuit or stage 206 that operates to adjust the gain of signal 204 to a suitable level. Gain adjustment circuit 206 may be provided because it may be difficult or impossible to integrate the input signal and adjust the gain to calibrate the unit in a single stage without affecting the internal / external signal ratio. Signal 208 output from gain adjustment circuit 206 may be provided to signal conditioning circuit or component 210, which operates to produce various output types, such as transient current, RMS current, etc., with various ranges or types of output levels (e.g., 0mA to 20mA, 4mA to 20mA, millivolts, volts). Figure 3 is a drawing view of a portion of an electrical parameter measuring device 300, illustrating an exemplary sensor arrangement of the device. In the illustrated embodiment, the device 300 includes 16 substantially identical sensors 304a to 304h (“sensors 304”) and sensors 306a to 306h (“sensors 306”) mounted on a support member 308 (such as a circuit board) of an electrically insulating material. Sensors 304 and 306 may be similar to or identical to sensors 104 and 106 discussed above with reference to Figure 1, respectively. Although not shown for clarity, sensors 304 and 306 may be coupled to appropriate circuitry to obtain measurement results therefrom, as discussed above. The support member 308 may include a slot 311 extending from its periphery beyond a point in the central region 314. Such a slot allows the conductor 302 under test to be introduced into the central region 314, wherein the axis of the conductor is orthogonal to the plane containing the sensors 304 and 306 (i.e., orthogonal to the plane of FIG. 3). Because at least some embodiments of this disclosure utilize magnetic field sensors without field concentrators as sensing elements, effects from field concentrators, such as hysteresis or nonlinearity, present in current transformers with magnetic cores, are absent. As discussed above, depending on the sensor type and internal sensor compensation (e.g., bridging circuitry), the current from the conductor under test 302 generates a voltage proportional to the magnetic field in sensors 304 and 306, allowing the measurement of DC current in addition to AC current. For AMR sensors or other types of sensors with relatively low saturation levels, in some embodiments, additional concentric sensor loops may be provided. This allows the device to switch to a larger concentric sensor loop with a lower magnetic field when there is a high current in the conductor being tested. For example, device 300 may include three or more concentric sensor loops, and two of the three or more loops may be used for the actual measurement to avoid saturation depending on the magnitude of the measured current. For larger currents, a pair of concentric sensor loops facing the outer periphery of the support member 308 may be used, while a pair of concentric sensor loops facing the center of the support member may be used for smaller currents. The size and dimensions of the opening formed by the slot can be designed in any suitable manner, and the slot can be fixed or selectively opened and closed (e.g., a clamp instrument with "jaws"). In at least some embodiments, the size and dimensions of the slot are designed to provide an opening with a diameter between 20 mm and 160 mm in the central region 314, although other sizes are available. Figures 4, 5A, and 5B illustrate another exemplary embodiment of a device 400 for positioning magnetic sensors using a multilayer printed circuit board. As schematically shown in Figure 4, a plurality of internal sensors 414 may be arranged in internal concentric rings and connected in series with each other, and a plurality of external sensors 416 may be arranged in external concentric rings and connected in series with each other. The number of sensors in each ring can be any suitable number of sensors, such as 4 sensors, 6 sensors, 8 sensors, 20 sensors, etc. The number of sensor PCBs 408 can be selected based on the required accuracy, position sensitivity, or external field suppression performance required for a particular application. As shown in Figures 5A and 5B, device 400 includes a plurality of sensor PCBs 408 mounted in a circle around a central portion 412 receiving a conductor 402 under test to a base or support PCB 410. Each sensor PCB 408 includes two separate sensors: an internal sensor 414 and an external sensor 416 constructed on a multilayer PCB 408. The sensor PCBs 408 are mounted to the base PCB 410 at right angles to the PCB 410. The outputs of sensors 414 are connected in series to provide an internal voltage Vinternal, and the outputs of sensors 416 are connected in series to provide an external voltage Vexternal. The advantages of the embodiments disclosed herein are that the measurement is performed non-invasively, and the sensor suppresses interference from other external fields injected from adjacent conductors outside the sensor. This measurement method offers significantly lower cost and higher performance / accuracy levels compared to other conventional measurement solutions. Furthermore, at least some of the embodiments discussed herein offer at least some of the following benefits: the ability to use coils as sensors to measure AC or pulsed DC currents, and the ability to use AMR sensors, Hall effect sensors, flux gate sensors, etc., to measure DC currents; low positional error depending on the number of planar sensors; lighter weight compared to current transformers; ability to handle high current overloads; low current consumption requirements; and isolated output signals due to complete current sensor isolation. These features make the embodiments discussed herein suitable for portable applications and power quality monitoring where weight and battery life are important design factors. Moreover, in at least some embodiments, air-core coils, such as Rogowski coils, can be used as sensing elements, meaning that hysteresis, saturation, or nonlinearity present, as in, for example, current transformers with magnetic cores, are absent. As discussed above, using semiconductor-based magnetic field sensors allows for DC current measurement in addition to AC current measurement. Any type of technique for measuring magnetic fields can be used, including the Hall effect, fluxgate magnetization, AMR, GMR, etc. Figure 6 is a schematic diagram illustrating an exemplary integrated dual-sensor 600 for an electrical parameter measuring device such as any of the electrical parameter measuring devices discussed herein. For example, the dual-sensor 600 can be used in place of each pair of radially spaced sensors 104 and 106 of the electrical parameter measuring device 100 of Figure 1. In this embodiment, sensor 600 includes an inner sensor 602 (“sensor A”) positioned relatively close to a central region 606 of the device, where a conductor under test (not shown) can be positioned during measurement. Sensor 600 also includes an outer sensor 604 (“sensor B”) positioned further away from the central region 606 than the inner sensor 602. The distance 'd' between sensors 602 and 604 is fixed. Therefore, while the sensitivity / suppression of the external current cannot be optimized or adjusted in this integrated sensor embodiment, the size and cost of sensor 600 are significantly reduced compared to two separate sensors radially separated from each other (such as sensors 104a and 106a of Figure 1). In at least some embodiments, the output of a single sensor can be used to determine the position of the conductor under test within the measurement area. Using magnetic fields detected from at least three sensors 600, triangulation can be used to determine the position of the conductor under test. If the position of the conductor is known, the influence of wires can be compensated for to further improve accuracy. Furthermore, in this arrangement, a combination of other sensors, such as a non-contact voltage sensor, can be used to determine the position or a combination of two triangulation results to verify position accuracy or even compensate for other influences, such as non-perpendicular wires to the sensor plane. Figure 7 is a schematic diagram illustrating an exemplary integrated dual-sensor 700 of an electrical parameter measuring device that enables the determination of the location of a conductor under test using only two sensors. Sensor 700 includes an inner sensor 702 spaced apart from a central measurement region 706 and an outer sensor 704 spaced further from the central region relative to the inner sensor 702. The inner sensor 702 includes sub-sensors A1 and A2 rotated 90 degrees relative to each other. Sensor 700 also includes the outer sensor 704, which includes sub-sensors B1 and B2 rotated 90 degrees relative to each other. The magnetic vector direction can be derived using sine and cosine functions, as discussed below with reference to Figure 8. Although sensors 702 and 704 are shown as integrated into sensor 700, in at least some embodiments, sensors 702 and 704 can be independent sensors, which improves design flexibility but increases sensor size and cost. Figure 8 is a schematic diagram 800 illustrating a technique that uses two sensors 802 and 804 (which may be similar to or the same as sensors 702 and 704, respectively) to determine the position of the conductor 806 under test within the measurement area of ​​an electrical parameter measuring device. As shown, using dual sensors indicating the direction of magnetic fields (H1, H2), perpendicular lines 808 and 810 to fields H1 and H2, respectively, can be calculated, and the intersection point 812 of the lines indicates the position of the conductor 806 under test. The physical location of a conductor can also be determined by mechanical means. For example, a wire positioning mechanism may include a wire passing through a small opening in an electrical parameter measuring device to a predetermined location. Therefore, in the event of a failure of one or more sensors, a mechanical means can be used to determine the physical location of the conductor. Figure 9 is a drawing of the front end of an electrical parameter measuring device 900 according to a non-limiting illustrative embodiment, showing the positions of a plurality of internal sensors 904 and external sensors 906 that can be used to determine the position of the conductor 902 under test or to determine one or more calibration factors, which depend on the position used to improve measurement accuracy. In this case, triangulation requires individual sensor output signals. As discussed above, sensors 904 and 906 can be mounted to a support member 908, and a slot 910 can be provided to allow the conductor 902 to be positioned within a central measurement area 914. If the position of conductor 902 is known, any position-related deviations of the conductor can be corrected by one or more position-related calibration factors. Additionally, signals from outside the measurement area 914 can be suppressed. The techniques for determining the position of conductor 902 and generating calibration factors are further discussed below with reference to a non-contact voltage embodiment of this disclosure. However, in this embodiment, a reference voltage is not required to generate a reference current because the magnitude of the current measured by sensors 904 and 906 can be used directly. To generate a calibration factor, a conductor 902 carrying a known current can be moved around a measurement area 914. The current generates a measured signal in multiple sensors 904 and 906, for example, at least three sensors. For each location, multiple sensor signals and calibration factors are stored in a table. This process can be repeated for multiple different current values ​​in conductor 902. Then, during operation, the table can be used to look up the conductor's location when measuring an unknown current, due to the ratio of the at least three measured sensor signals, which then provides the calibration factor. The calibration factor can be interpolated between defined discrete values ​​(e.g., x / y positions for calibration). This concept can be used in one or more (e.g., two, three, four) sensor rings of an electrical parameter measurement device. Figure 10 is a schematic diagram of the front end of an electrical parameter measuring device 1000 including multiple independent sensors 1002a to 1002h, which are calibrated and measured independently of the other sensors around a measurement area 1004. This configuration can further improve performance (e.g., accuracy, linearity, position sensitivity) by individually calibrating each sensor 1002 to deliver a precisely calibrated output signal with respect to the magnetic field. In the illustrated example, each of the sensors 1002a to 1002h is coupled via conductor 1006 to different inputs B1 to B8 of circuit 1008. Circuit 1008 may be a microcontroller or other suitable circuitry including input circuitry (e.g., an A / D converter, etc.) capable of receiving signals output from the sensors 1002a to 1002h. Each sensor 1002 is measured independently of the other sensors. That is, the sensors 1002 are not connected in series in an inner and outer ring as discussed above for other embodiments. Although eight sensors 1002 are shown in Figure 10 as an example, in other embodiments, fewer or more sensors may be used, and two or more concentric sensor rings may be provided. Furthermore, as discussed above, sensor measurements (e.g., in the rings) may be summed or averaged to produce the desired measurement output. In at least some embodiments, the range of sensor 1002, such as an AMR sensor, can be extended to compensate for saturation effects under high magnetic fields. Individual sensors near the conductor that will reach high saturation can be excluded from the measurement integral, and the value can be interpolated by two adjacent sensors. If each sensor has been calibrated, and not just the total output signal, the sum of all sensor information from the outer and inner sensor loops may be more accurate. If the saturation effect of an individual sensor is too high to achieve reasonable results, the signal from that sensor can be ignored and / or interpolated from neighboring sensors. The following example illustrates the interpolation calculation for saturating "Sensor 2" located between "Sensor 1" and "Sensor 3" in the sensor ring. Wherein, W(sensor X) is a calibration factor for the determined conductor position of sensor X (e.g., sensor 1, 2, 3, ..., 8). In this exemplary embodiment, using at least three of eight possible sensor signals, triangulation allows the location of the conductor under test to be determined based on the magnetic field distribution. This feature also enables the identification of whether the conductor is located inside or outside the measurement area, allowing conductors located outside the measurement area to be ignored. The features discussed above can be combined with the non-contact voltage sensors discussed below to deliver more information about the position of the conductor under test and also improve the reliability of the position information. The circular magnetic field of the wires inside the sensor can be affected by adjacent, additional external wires carrying the current. However, non-contact voltage information for wire location is more accurate than current measurement, which is unaffected by external electric fields, due to the easier electric field shielding compared to the B field. Additionally, the location of more than one conductor can be calculated. The actual number of conductors that can be identified simultaneously may depend on the number of voltage and / or current sensors used for a particular application. Reference signal type non-contact voltage measurement equipment The following discussion provides examples of systems and methods for measuring alternating current (AC) voltage in insulated conductors (e.g., insulated wires) or uninsulated bare conductors (e.g., busbars) without requiring a current connection between the conductor and the test electrodes or probes. The embodiments disclosed in this section may be referred to herein as “reference signal type voltage sensors” or systems. Generally, non-current contact (or “non-contact”) voltage measuring devices are provided that use a capacitance sensor to measure the AC voltage signal in an insulated conductor relative to ground. Such systems that do not require a current connection are referred to herein as “non-contact.” As used herein, “electrical coupling” includes direct electrical coupling and indirect electrical coupling, unless otherwise stated. Although the following discussion primarily describes non-contact reference signal type measuring devices, it should be understood that the calibration systems and methods disclosed herein may be additionally or alternatively used to calibrate contact reference signal voltage measuring devices (e.g., digital multimeters (DMMs) that generate and detect reference signals). Therefore, the following discussion can be applied to the calibration subsystem of a measuring device that can be used to determine one or more calibration factors and / or the position of the conductor under test, as well as the measurement subsystem of a measuring device that can be used to obtain measurement results of one or more electrical parameters (e.g., voltage, current, power). Figure 11A is a drawing of environment 1100 in which an operator 1104 can use a non-contact voltage measuring device 1102, including a reference signal type voltage sensor or system, to measure the AC voltage present in an insulated wire 1106 without requiring current contact between the non-contact voltage measuring device and the wire 1106. Figure 11B is a top plan view of the non-contact voltage measuring device 1102 of Figure 11A, showing various electrical characteristics of the non-contact voltage measuring device during operation. The non-contact voltage measuring device 1102 includes a housing or body 1108, which includes a gripping portion or end 1110 and a probe portion or end 1112 opposite the gripping portion, also referred to herein as a front end. The housing 1108 may also include a user interface 1114 to facilitate user interaction with the non-contact voltage measuring device 1102. The user interface 1114 may include any number of inputs (e.g., buttons, dials, switches, touch sensors) and any number of outputs (e.g., displays, LEDs, speakers, buzzers). The non-contact voltage measuring device 1102 may also include one or more wired and / or wireless communication interfaces (e.g., USB, Wi-Fi®, Bluetooth®). In at least some embodiments, as best shown in FIG11B, the probe portion 1112 may include a recess 1116 defined by a first extension 1118 and a second extension 1120. The recess 1116 receives an insulated wire 1106 (see FIG11A). The insulated wire 1106 includes a conductor or wire 1122 and an insulator 1124 surrounding the conductor 1122. When the insulated wire 1106 is positioned within the recess 1116 of the non-contact voltage measuring device 1102, the recess 1116 may include a sensor or electrode 1126 disposed near the insulator 1124 of the insulated wire 1106. Although not shown for clarity, the sensor 1126 may be disposed inside the housing 1108 to prevent physical and electrical contact between the sensor and other objects. Furthermore, although a single sensor 1126 is shown in this example, in other embodiments, multiple spaced-apart sensors may be provided, as discussed below. As shown in Figure 11A, in use, the operator 1104 can grip the gripping portion 1110 of the housing 1108 and position the probe portion 1112 close to the insulated wire 1106, allowing the non-contact voltage measuring device 1102 to accurately measure the AC voltage present in the wire relative to the ground (or another reference node). Although the probe tip 1112 is shown as having a recessed portion 1116, in other embodiments, the probe portion 1112 may be configured differently. For example, in at least some embodiments, the probe portion 1112 may include a selectively movable clamp, hook, flat or arcuate surface including a sensor, or other types of interfaces that allow the sensor of the non-contact voltage measuring device 1102 to be positioned close to the insulated wire 1106. Examples of various probe portions and sensors are discussed below. In some implementations, the operator's body may act as a ground / ground reference. Alternatively, a direct connection via test lead 1139 to ground or grounding portion 1128 may be used. The non-contact measurement capabilities discussed herein are not limited to applications measuring only relative to ground. An external reference may be capacitively coupled or directly coupled to any other potential. For example, if an external reference is capacitively coupled to another phase in a three-phase system, the phase-to-phase voltage is measured. In general, the concepts discussed herein are not limited to using only body capacitive coupling connected to a reference voltage and any other reference potential for a ground reference. As further discussed below, in at least some embodiments, the non-contact voltage measuring device 1102 can utilize the body capacitance (CB) between the operator 1104 and the ground 1128 during AC voltage measurement. Although the term ground is used for node 1128, this node is not necessarily ground / grounded, but can be connected to any other reference potential in a current-isolated manner via capacitive coupling. The specific system and method used by the non-contact voltage measuring device 1102 to measure AC voltage are discussed below with reference to Figures 12 to 14. Figure 12 shows a schematic diagram of the various internal components of the non-contact voltage measuring device 1102, also shown in Figures 11A and 11B. In this example, the conductivity sensor 1126 of the non-contact voltage measuring device 1102 is generally “V”-shaped and positioned close to the insulated wire 1106 under test, and is capacitively coupled to the conductor 1122 of the insulated wire 1106, thereby forming a sensor coupling capacitor (CO). The operator 1104 operating the non-contact voltage measuring device 1102 has a body capacitance (CB) to ground. As shown in Figures 11A and 11B, direct conductive ground coupling through a wire (e.g., test lead 1139) can also be used. Thus, as shown in Figures 11B and 12, the AC voltage signal (VO) in the wire 1122 generates an insulated conductor current component, or “signal current” (IO), through the series-connected coupling capacitor (CO) and body capacitance (CB). In some embodiments, the body capacitance (CB) may also include a test lead that provides current isolation to ground or any other reference potential. The AC voltage (VO) in the wire 1122 to be measured has a connection to an external ground 1128 (e.g., neutral wire). The non-contact voltage measuring device 1102 itself also has capacitance to the ground 1128, which is mainly composed of a body capacitance (CB) when the operator 1104 (FIG. 11) holds the non-contact voltage measuring device in their hand. Both capacitances CO and CB form a conductive loop, and the voltage within this loop generates a signal current (IO). The signal current (IO) is generated by the AC voltage signal (VO) capacitively coupled to the conductivity sensor 1126 and returns to the external ground 1128 through the housing 1108 of the non-contact voltage measuring device and the body capacitor (CB) to the ground 1128. The current signal (IO) depends on the distance between the conductivity sensor 1126 of the non-contact voltage measuring device 1102 and the insulated wire 1106 under test, the specific shape of the conductivity sensor 1126, and the size and voltage level (VO) of the conductor 1122. To compensate for the distance variance that directly affects the signal current (IO) and the resulting coupling capacitor (CO) variance, the non-contact voltage measurement device 1102 includes a common-mode reference voltage source 1130 that generates an AC reference voltage (VR) having a reference frequency (fR) different from the signal voltage frequency (fO). To reduce or avoid stray currents, at least a portion of the non-contact voltage measuring device 1102 may be surrounded by a conductive internal grounding shield or cover 1132, which allows most of the current to flow through the conductive sensor 1126, which forms a coupling capacitor (CO) with the conductor 1122 of the insulated wire 1106. The internal grounding shield 1132 may be formed of any suitable conductive material (e.g., copper) and may be solid (e.g., foil) or have one or more openings (e.g., mesh). Furthermore, to prevent current from flowing between the internal grounding shield 1132 and the external grounding portion 1128, the non-contact voltage measuring device 1102 includes a conductive reference shield 1134. The reference shield 1134 can be formed of any suitable conductive material (e.g., copper) and can be solid (e.g., a sheet of metal, sputtered metal inside a plastic housing), flexible (e.g., a foil), or have one or more openings (e.g., a mesh). A common-mode reference voltage source 1130 is electrically coupled between the reference shield 1134 and the internal grounding shield 1132, which generates a common-mode voltage or reference signal with a reference voltage (VR) and a reference frequency (fR) for the non-contact voltage measuring device 1102. This AC reference voltage (VR) drives an additional reference current (IR) through a coupling capacitor (CO) and a body capacitor (CB). An internal ground shield 1132 surrounding at least a portion of the conductivity sensor 1126 protects the conductivity sensor from the direct influence of an AC reference voltage (VR), which causes an undesirable shift in the reference current (IR) between the conductivity sensor 1126 and the reference shield 1134. As described above, the internal ground shield 1132 is an internal electronic ground portion 1138 for the non-contact voltage measurement device 1102. In at least some embodiments, the internal ground shield 1132 also surrounds some or all of the electronics in the non-contact voltage measurement device 1102 to prevent the AC reference voltage (VR) from coupling into the electronics. As described above, the reference shield 1134 is used to inject a reference signal into the input AC voltage signal (VO) and, as a secondary function, to minimize the capacitance of the shield 1132 to the grounding portion 1128. In at least some embodiments, the reference shield 1134 surrounds part or all of the housing 1108 of the non-contact voltage measuring device 1102. In such embodiments, part or all of the electronics in the device references a common-mode signal that also generates a reference current (IR) between the conductivity sensor 1126 and the conductor 1122 in the insulated wire 1106. In at least some embodiments, the only gap in the reference shield 1134 may be an opening for the conductivity sensor 1126, which allows the conductivity sensor to be positioned close to the insulated wire 1106 during operation of the non-contact voltage measuring device 1102. Internal grounding shield 1132 and reference shield 1134 provide a double-layer shielding around the housing 1108 (see Figures 11A and 11B) of the non-contact voltage measurement device 1102. Reference shield 1134 may be disposed on the outer surface of housing 1108, and internal grounding shield 1132 may act as an internal shield or shield. The conductivity sensor 1126 is shielded by reference shield 1134 via shield 1132, such that any reference current is generated by the coupling capacitor (CO) between the conductivity sensor 1126 and the conductor under test 1122. Shield 1132 surrounding the sensor 1126 also reduces stray effects from adjacent wires near the sensor. As shown in Figure 12, the non-contact voltage measuring device 1102 may include an input amplifier 1136 operating as an inverting current-to-voltage converter. The input amplifier 1136 has a non-inverting terminal electrically coupled to an internal grounding shield 1132 that serves as an internal grounding portion 1138 of the non-contact voltage measuring device 1102. The inverting terminal of the input amplifier 1136 may be electrically coupled to a conductivity sensor 1126. A feedback circuit 1137 (e.g., a feedback resistor) may also be coupled between the inverting terminal and the output terminal of the input amplifier 1136 to provide feedback and appropriate gain for input signal conditioning. Input amplifier 1136 receives a signal current (IO) and a reference current (IR) from conductivity sensor 1126 and converts the received current into a sensor current voltage signal that indicates the conductivity sensor current at the output terminal of the input amplifier. This sensor current voltage signal may, for example, be an analog voltage. This analog voltage may be fed to signal processing module 1140, which, as discussed further below, processes the sensor current voltage signal to determine the AC voltage (VO) in conductor 1122 of insulated wire 1106. Signal processing module 1140 may include any combination of digital and / or analog circuitry. The non-contact voltage measurement device 1102 may also include a user interface 1142 (e.g., a display) communicatively coupled to the signal processing module 1140 to present a defined AC voltage (VO) or to the operator 1104 of the non-contact voltage measurement device via the interface. Figure 13 is a block diagram of a non-contact voltage measuring device 1300, showing the various signal processing components of the device. Figure 14 is a more detailed schematic diagram of the non-contact voltage measuring device 1300 of Figure 13. The non-contact voltage measuring device 1300 may be similar to or the same as the non-contact voltage measuring device 1102 discussed above. Therefore, similar or identical components are labeled with the same reference numerals. As shown, the input amplifier 1136 converts the input current (IO+IR) from the conductivity sensor 1126 into a sensor current-voltage signal indicating the input current. The sensor current-voltage signal is converted into digital form using an analog-to-digital converter (ADC) 1302. The AC voltage (VO) in wire 1122 is related to the AC reference voltage (VR) by equation (2): (2) Where (IO) is the signal current through the conductive sensor 1126 due to the AC voltage (VO) in conductor 1122, (IR) is the reference current through the conductive sensor 1126 due to the AC reference voltage (VR), (fO) is the frequency of the AC voltage (VO) being measured, and (fR) is the frequency of the reference AC voltage (VR). The signal labeled "O" associated with the AC voltage (VO) has different characteristics, such as frequency, than the signal labeled "R" associated with the common-mode reference voltage source 1130. In the embodiment of Figure 14, digital text processing, such as circuitry implementing a Fast Fourier Transform (FFT) 1306, can be used to separate signal magnitude values ​​with different frequencies. In other embodiments, analog electronic filters can also be used to separate the characteristics (e.g., magnitude, frequency) of the "O" signal from those of the "R" signal. The currents (IO) and (IR) depend on the frequencies (fO) and (fR) respectively due to the coupling capacitor (CO). The current flowing through the coupling capacitor (CO) and the body capacitance (CB) is proportional to the frequency, and therefore it is necessary to measure the frequency (fO) of the AC voltage (VO) in the conductor 1122 under test to determine the ratio of the reference frequency (fR) to the signal frequency (fO), which is used in equation (2) listed above, or the reference frequency is known because it is generated by the system itself. After the input current (IO+IR) has been regulated by the input amplifier 1136 and digitized by the ADC 1302, the frequency components of the digital sensor current-voltage signal can be determined by using the FFT 1306 to represent the signal in the frequency domain (see Figure 17). Once both frequencies (fO) and (fR) have been measured, a frequency window can be determined to calculate the fundamental values ​​of the current (IO) and (IR) from the FFT 1306. The magnitudes of the current (IR) and / or current (IO) can vary as a function of the distance between the reference signal sensor or electrode (e.g., electrode 1126) and the conductor 1122 of the insulated wire 1106. Therefore, the system can compare the measured current (IR) and / or current (IO) with the expected corresponding current to determine the distance between the reference signal sensor or electrode and the conductor 1122. Next, as indicated by box 1308 in Figure 13, the ratio of the fundamental harmonics of the currents (IR) and (IO), designated as IR, 1 and IO, 1 respectively, can be corrected by determining the frequencies (fO) and (fR), and this factor can be used to calculate the measured original fundamental or RMS voltage by adding harmonics (VO) to the wire 1122, which is done by calculating the square root of the sum of square harmonics and can be presented to the user on the display 1312. The coupling capacitor (CO) can typically have a capacitance value ranging from about 0.02 pF to 1 pF, for example, depending on the distance between the insulated wire 1106 and the conductive sensor 1126, as well as the specific shape and size of the sensor 1126. The bulk capacitor (CB) can, for example, have a capacitance value ranging from about 20 pF to 200 pF. As can be seen from equation (2) above, the AC reference voltage (VR) generated by the common-mode reference voltage source 1130 does not need to be in the same range as the AC voltage (VO) in conductor 1122 to achieve similar signal current (IO) and reference current (IR) values. By selecting a relatively high reference frequency (fR), the AC reference voltage (VR) can be relatively low (e.g., less than 5V). For example, the reference frequency (fR) can be selected as 3kHz, which is 50 times higher than the typical 1120 VRMS AC voltage (VO) with a signal frequency (fO) of 60Hz. In this case, the AC reference voltage (VR) can be selected as only 2.4V (i.e., 1120 V ÷ 50) to generate the same reference current (IR) as the signal current (IO). Generally speaking, setting the reference frequency (fR) to N times the signal frequency (fO) allows the AC reference voltage (VR) to have a value that is (1 / N) times the AC voltage (VO) in wire 1122, so as to produce currents (IR) and (IO) in the same range as each other, thereby achieving similar uncertainties in IR and IO and avoiding mathematical inaccuracies in the ratio I0 / IR. Any suitable signal generator can be used to generate an AC reference voltage (VR) with a reference frequency (fR). In the example shown in Figure 13, a Σ-Δ digital-to-analog converter (Σ-Δ DAC) 1310 is used. The Σ-Δ DAC 1310 uses a bitstream to generate a waveform (e.g., a sine wave) signal with a defined reference frequency (fR) and AC reference voltage (VR). In at least some embodiments, the Σ-Δ DAC 1310 can generate a waveform in phase with the window of the FFT 1306 to reduce jitter. Any other reference voltage generator can be used, such as a PWM that uses less computational power than the Σ-Δ DAC. In at least some implementations, the ADC 1302 may have a 14-bit resolution. In operation, for a nominal 50Hz input signal, the ADC 1302 may sample the output from the input amplifier 1136 at a sampling frequency of 10.24kHz to provide 2^n samples (2024) in 1100ms (a 10Hz window of the FFT 1306) ready for processing by the FFT 1306. For a 60Hz input signal, the sampling frequency may be, for example, 12.288kHz to obtain the same number of samples per cycle. The sampling frequency of the ADC 1302 may be synchronized with the full cycle of a reference frequency (fR). For example, the input signal frequency may be in the range of 40Hz to 70Hz. Depending on the frequency of the AC voltage (VO) being measured, the FFT 1306 may be used to determine the window for the AC voltage (VO), and further calculations may be performed using a Hanning window function to suppress phase shift jitter caused by incomplete signal cycles captured in the aggregation interval. In one example, the common-mode reference voltage source 1130 generates an AC reference voltage (VR) with a reference frequency (fR) of 2419 Hz. For a 60 Hz signal, this frequency lies between the 40th and 41st harmonics, and for a 50 Hz signal, it lies between the 48th and 49th harmonics. By providing an AC reference voltage (VR) with a reference frequency (fR) that is not the expected AC voltage (VO), the AC voltage (VO) is less likely to affect the measurement of the reference current (IR). In at least some embodiments, the reference frequency (fR) of the common-mode reference voltage source 1130 is selected as the frequency least likely to be affected by harmonics of the AC voltage (VO) in the conductor under test 1122. For example, the common-mode reference voltage source 1130 can be turned off when the reference current (IR) exceeds a limit (which could indicate that the conductivity sensor 1126 is approaching the conductor under test 1122). Measurements can be performed with the common-mode reference voltage source 1130 turned off (e.g., a 1100 ms measurement) to detect signal harmonics at a number of candidate reference frequencies (e.g., three, five). The magnitude of the signal harmonics in the AC voltage (VO) can then be determined at these candidate reference frequencies to identify which candidate reference frequency is least likely to be affected by the signal harmonics of the AC voltage (VO). The reference frequency (fR) can then be set to the identified candidate reference frequency. This switching of the reference frequency avoids or reduces the influence of possible reference frequency components in the signal spectrum, which can increase the measured reference signal and reduce accuracy, and may produce unstable results. Other frequencies with the same characteristics besides 2419 Hz include, for example, 2344 Hz and 2679 Hz. To avoid gaps in the measurement sequence when the reference voltage source is turned off, previously measured reference values ​​can be used together with the actual signal values. Further improvements can be made if the difference between the actual signal and the previously measured signal is applied to the reference signal used for the turn-off measurement in the same proportion. Assuming the moving average does not change from one measurement result to another, perhaps only the distance sensor-wire (coupling capacitor) will change, thus affecting both signals (reference signal, input signal) in the same proportion. Calibration System and Method As discussed above, the reference voltage (VR) and reference frequency (fR) generated by the voltage measuring device are known and can be measured at the output of the reference voltage source 1130 (Figure 12). The output voltage (VO) is defined by equation (2) above. Ideally, if the reference voltage (VR) is known and all other required parameters are the ratio IO / IR and fR / fO, then the voltage measuring device does not need to be calibrated. However, in practice, several influencing factors exist, such as the bandwidth of the signal processing circuit, leakage capacitance, and the specific position of the conductor under test relative to the measuring device, which cause the output voltage measurement to deviate from the actual output voltage in the conductor under test. One factor is the stray leakage capacitance between the sensor 1126 (or multiple sensors) and the environment, which tends to increase the reference current (IR) and thus decrease the ratio IO / IR. In addition, the direct capacitive coupling between the sensor 1126 and the reference shield 1134 causes a further increase in the offset of the reference current (IR). Such an increase in the ideal reference current (IR) results in a calculated output voltage (VO) that is less than the actual output voltage in the conductor under test. Therefore, the calibration systems and methods discussed herein allow for accurate measurement of the output voltage (VO) or other parameters in the conductor under test using determined calibration parameters or factors that depend on the coupling capacitance (CO) or, equivalently, the distance between each of one or more sensors and the conductor under test. As further discussed below, in at least some embodiments, multiple sensors are utilized, and the position of the conductor under test is determined by triangulation of the reference current measured by the multiple sensors. Figure 15 shows a schematic block diagram of an exemplary calibration system 1500 that can be used to calibrate an electrical parameter measuring device 1502 (e.g., a DMM, current clamp, or split-core transformer). The electrical parameter measuring device 1502 can be any non-contact or contact measuring device, such as a measuring device that generates and senses a reference signal. The calibration system 1500 may include control circuitry 1504 that controls various functionalities of the calibration system. The calibration system 1500 may also include a calibration voltage source 1506 that operates to selectively output a calibration or test voltage to a calibration conductor 1508. The control circuitry 1504 is operatively coupled to the calibration voltage source 1506 to control its operation. The calibration system 1500 also includes a position control subsystem 1510 that operates to selectively mechanically control the position of the calibration conductor 1508 relative to the electrical parameter measuring device 1502 during calibration. The calibration conductor 1508 may be an insulated conductor for calibrating non-contact electrical parameter measuring devices or a non-insulated conductor for calibrating contact-type electrical parameter measuring devices. The control circuit 1504 of the calibration system 1500 can be operatively coupled to the electrical parameter measuring device 1502 via any suitable wired or wireless connection. As further discussed below, the control circuit 1504 is operable to send or receive instructions or data from the electrical parameter measuring device 1502. The control circuit 1504 controls the position control subsystem 1510 to selectively adjust the position of the calibration conductor 1508 within an opening or receiving portion at the front or measuring end of the electrical parameter measuring device, such that the capacitive coupling CO between each of the plurality of sensors and the calibration conductor is altered to modify the corresponding reference current IR of the plurality of sensors, thereby obtaining different calibration points for multiple physical locations of the calibration conductor 1508. Generally, control circuitry 1504 may include at least one processor communicatively coupled to at least one non-transitory processor-readable storage medium of calibration voltage source 1506, position control subsystem 1510, and storage of at least one of processor-executable instructions or data. Control circuitry 1504 may include any type of processing unit, such as one or more central processing units (CPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), programmable logic controllers (PLCs), artificial neural network circuits or systems, or any other discrete or integrated logic components. The non-transitory processor-readable storage medium coupled to control circuitry 1504 may include any type of non-transitory volatile and / or non-volatile memory. In at least some embodiments, the control circuitry 1504 may include a communication interface or a user interface. The user interface facilitates interaction between a user and the calibration system 1500. The user interface may include any number of inputs (e.g., buttons, dials, switches, touch sensors) and any number of outputs (e.g., displays, LEDs, speakers, buzzers). For example, the user interface may include inputs that allow an operator to modify one or more adjustable settings of the calibration system 1500 or the electrical parameter measuring device 1502. The communication interface may implement one or more wired and / or wireless communication technologies (e.g., USB, Wi-Fi®, Bluetooth®) that allow the calibration system 1500 to communicate with the electrical parameter measuring device 1502 or one or more local or remote external processor-based devices. In at least some embodiments, the output voltage (VO) measurement of the electrical parameter measuring device 1502 may depend on the measured reference current signal (IR) and / or the actual output voltage in the conductor under test. Therefore, in at least some embodiments, the calibration systems and methods discussed herein provide compensation for one or both of these parameters to allow accurate measurement of various voltages of the conductor under test relative to the electrical parameter measuring device 1502 and the output voltage (VO) at various locations corresponding to various combinations of reference current (IR) levels of multiple sensors (e.g., two sensors, three sensors) of the electrical parameter measuring device 1502. Generally, during the calibration process, control circuit 1504 controls calibration voltage source 1506 to output a known calibration voltage (e.g., 110VAC, 250VAC, 1800VAC) to calibration conductor 1508 and controls position control system 1510 to move the calibration conductor to a known position (e.g., X / Y position) within the front end or measurement section of electrical parameter measuring device 1502. Control circuit 1504 then receives data acquired by the electrical parameter measuring device 1502 during the measurement of the calibration voltage in calibration conductor 1508. Such data may include reference current signals (IR) for measurements of multiple sensors, determined output voltages (VO), etc. Electrical parameter measuring device 1502 may acquire such data, for example, in a manner discussed above with reference to Figures 11A to 14. This process can be repeated multiple times when calibration conductor 1508 is in different positions and optionally at different calibration voltages. For each of the plurality of locations of the calibration conductor 1508 and for each of the plurality of calibration voltages (e.g., 110VAC, 250VAC, 1000VAC), the control circuit 1504 may obtain a plurality of calibration points associated with the calibration voltage. In at least some embodiments, each calibration point includes a reference current signal data point and a calibration factor for each of the respective plurality of sensors of the electrical parameter measuring device. The reference current signal data point is a measurement result obtained from the sensors of the electrical parameter measuring device 1502, indicating the reference current signal measured by the sensors of the electrical parameter measuring device when the calibration voltage source 1506 outputs a calibration voltage in the calibration conductor 1508. The calibration factor may be a value indicating the ratio of a known calibration voltage to a measured uncalibrated output voltage (VO) data point obtained from the sensors of the electrical parameter measuring device, which is determined by the electrical parameter measuring device at least in part based on the reference current signal data point of the sensor (e.g., using equation (2) above). For example, if control circuit 1504 causes calibration voltage source 1506 to output 1100V in calibration conductor 1508, and the sensor of electrical parameter measuring device 1502 measures an output voltage of 1110V, then the calibration factor will be 1100 / 1110 = 0.909. For a specific measurement, the uncalibrated output voltage measured by electrical parameter measuring device 1502 can be multiplied by the calibration factor to provide the correct output voltage. Continuing with the example above, an uncalibrated output voltage of 1110VAC can be multiplied by a calibration factor of 0.909 to provide an actual output voltage of 1100VAC in the conductor under test. As further discussed below, after obtaining calibration points, control circuitry 1504 can determine calibration data for electrical parameter measuring device 1502 based on the obtained multiple calibration points. The calibration data may depend on reference current signals measured by multiple sensors of the electrical parameter measuring device. In at least some embodiments, the calibration data may also depend on multiple calibration voltages. Control circuitry 1504 can then store the calibration data on at least one non-transitory processor-readable storage medium associated with electrical parameter measuring device 1502 for use by the electrical parameter measuring device or other electrical parameter measuring devices (e.g., having the same or similar physical characteristics) during their subsequent operation. For example, calibration data may include one or more lookup tables and / or coefficients for one or more mathematical formulas. Figure 16 is a schematic diagram of the V-shaped front end 1600 of the electrical parameter measuring device, showing three conductivity sensors 1604, 1606, and 608 mounted on the protective member 1602 for determining the position of the conductor 1610 under test. The values ​​of reference currents 1612, 1614, and 616 measured by sensors 1604, 1606, and 608 are also shown, where each constant reference current is represented by a dashed arc with a specific distance, indicating the constant reference current value that indicates the possible position of the conductor 1610 under test determined by the sensors. As shown, the three reference currents 1612, 1614, and 616 intersect at the X / Y position of the conductor 1610 under test. Therefore, by using triangulation measurements of the reference currents 1612, 1614, and 616 with the three sensors 1604, 1606, and 608, the position of the conductor 1610 under test can be accurately determined. As discussed further below, location determination can be used to select or derive calibration factors for electrical parameter measurements to be applied to an electrical parameter measuring device. For example, a prior calibration process can be performed to define a set of discrete data points, such as a calibration grid, specifying calibration factors for any possible location of the conductor under test. This calibration process can result in location coordinates (reference currents IREF1, IREF2, IREF3 for each of the sensors in sensors 1604, 1606, and 608, respectively) and calibration factors (e.g., VCAL1, VCAL2, VCAL3) indicating the amount of correction to be applied to the measurement results of electrical parameters (e.g., current, voltage, power). Similar to equation (2) above, the unknown signal voltage VO can be calculated as follows: (3) Where V CALX is the calibration factor of sensor X (i.e., X=1, 2, 3), I OX is the signal current from each sensor, f OX is the signal frequency measured by each of the three sensors (e.g., 50Hz, 60Hz), V REF is the common-mode reference voltage generated inside the electrical parameter measuring device, and f R is the frequency of the reference voltage. Figure 17 is a schematic diagram of the V-shaped front end 1700 of the electrical parameter measuring device, showing two conductivity sensors 1704 and 1706 disposed on the protective member 1702 for determining the position of the conductor 1708 under test, wherein the position of the two conductivity sensors allows for accurate position determination of the conductor under test. In contrast, Figure 18 is a schematic diagram of the V-shaped front end 1800 of the electrical parameter measuring device, showing two conductivity sensors 1804 and 1806 disposed on the protective member 1802 for determining the position of the conductor 1808 under test, wherein the position of the two conductivity sensors can lead to ambiguous or inaccurate position determination of the conductor under test. Referring to Figure 17, sensor 1704 is positioned at the bottom or base portion of the protective member 1702, and sensor 1706 is positioned on the left side or left portion of the protective member (as shown). A first curved dashed line 1710 represents the constant reference current value detected by sensor 1704, and a second curved dashed line 1712 represents the constant reference current value detected by sensor 1706. As shown, curves 1710 and 1712 intersect at only one location, which is the location of the conductor 1708 under test. That is, another theoretical intersection of curves 1710 and 1712 will be outside the V-shaped protective member 1702 and can therefore be ignored by the measuring device because this location is not a possible location of the conductor 1708 under test. Therefore, since there is only one possible intersection of curves 1710 and 1712, the measuring device can accurately determine the location of the conductor 1708 under test. Referring now to Figure 18, sensor 1804 is positioned on the left side or left portion of the protective element 1802 (as shown), and sensor 1806 is positioned on the right side or right portion of the protective element opposite to the left side (as shown). A first curved dashed line 1810 represents the constant reference current value detected by sensor 1804, and a second curved dashed line 1812 represents the constant reference current value detected by sensor 1806. As shown, curves 1810 and 1812 intersect at two locations: the actual position of the conductor 1808 under test and a second position 1809 facing the base of the protective element. In this case, because there are two intersection points, the measuring device may have difficulty determining the location of conductor 1808. This problem can be remedied by carefully selecting the positions of the two sensors, as in the example of Figure 17, so that there is only one curve intersection point inside the protective element, or by using three sensors, as discussed above in the example of Figure 16. Figure 19 is a schematic diagram of the front end 1900 of the electrical parameter measuring device, showing two conductivity sensors 1904 and 906 that are coplanar with each other on a planar protective member 1902 and can be used to determine the position of the conductor 1908 under test. Constant reference current curves 1910 and 912 for sensors 1904 and 906, respectively, are also shown. By placing sensors 1904 and 906 so that they are coplanar with respect to each other, curves 1910 and 912 intersect each other only at one permissible location (i.e., above the protective member 1902), thus avoiding ambiguity that could be caused by two sensors arranged such that the constant reference current curves intersect at two permissible locations as shown in the example of Figure 18. Figure 20 is a schematic diagram of the V-shaped front end 2000 of an electrical parameter measuring device including three conductivity sensors 2004, 2006, and 2008 disposed on a protective element 2002, showing various possible positions 2012 of the conductor 2010 under test. The various positions 2012 can be calibration positions or points that can be used to obtain calibration data during the calibration process. For example, when the calibration conductor is positioned at each of the calibration positions 2012, the electrical parameter measuring device can obtain the X / Y position of the calibration conductor, the reference current IREFX of each of the sensors 2004, 2006, and 2008, and a calibration factor CALFAC indicating the correction to be applied to obtain accurate parameter measurement results. Figure 21 is a table 2100 showing the position-related calibration factors of the three conductive sensors 2004 (sensor 1), 2006 (sensor 2), and 1008 (sensor 3) of Figure 20 at various X / Y positions. As shown, for each X / Y position, a reference current IREFX and a calibration factor VCALS are determined for each of the three conductive sensors 2004 (sensor 1), 2006 (sensor 2), and 1008 (sensor 3). Figure 22 is a table 2200 showing the position-dependent calibration factor (CALF) and reference current signal (ref_pk) of a single conductivity sensor (e.g., one of sensors 2004, 2006, or 1008) when the conductor under test is positioned at various distances (DIST) from the conductivity sensor. Figure 23 is a graph 2300 showing the reference current signal (ref_pk) and calibration factor (CALF) as a function of distance (in millimeters (mm)). As shown, the reference signal decreases rapidly with distance, while the calibration factor increases with distance. As can be clearly seen from graph 2300, the reference current (ref_pk) exhibits a form of 1 / x behavior. Therefore, it is advantageous to plot the reciprocal of the reference current (i.e., 1 / ref_pk) to obtain a simplified and appropriately accurate representation. Figure 2400 is a graph showing the linear approximation of the reciprocal of the reference current signal as a function of distance (i.e., 1 / ref_pk) and the quadratic approximation of the calibration factor CALF. As the R² values ​​for the linear and quadratic approximations are 0.9957 and 0.999, respectively, each of the two approximations accurately represents the corresponding reciprocal of the reference current signal as a function of distance and the calibration factor. Figure 25 is a graph of the calibration factor (CALF) as a function of the reciprocal of the reference current signal (i.e., 1 / ref_pk). As shown in the figure, the points are approximated by a closely fitted quadratic function with an R² value of 1.000. Figures 26A and 26B show a portion of the front end 2600 of an electrical parameter measuring device including a V-shaped guard 2602 supporting two elongated conductive sensors 2604 and 2606, which are designated as the left sensor and right sensor, respectively, for illustrative purposes. Specifically, the guard 2602 includes a left portion 2602a (as shown) supporting the left sensor 2604 and a right portion 2602b supporting the right sensor 2606. Each of the sensors 2604 and 2606 has a length dimension and a width dimension, with the length dimension being greater than the width dimension. As a non-limiting example, the aspect ratio may be 1.5:1, 2:1, 4:1, 8:1, 20:1, 1100:1, etc. Since sensors 2604 and 2606 are elongated, it can be assumed or estimated that the only change in the detected signal originates from the normal distance between the conductor under test and each of the sensors, making the effect caused by lateral movement at a constant normal distance negligible. Based on a mathematical simplification representing the distance correlation between the reference current ref_pk and the calibration factor CALF, a measurement grid fitted within the region of the V-shaped front end 2600 can be generated. In one example, assume that sensor 2604 is a straight line segment extending from point A (X=-2; Y=-35) to point B (X=-35; Y=+45) in the X / Y coordinate system, and assume that sensor 2606 is a straight line segment extending from point A' (X=+2; Y=-35) to point B (X=+35; Y=+45) in the X / Y coordinate system. For each point, the normal distance to the left sensor 2604 and the right sensor 2606 can be calculated, and the reference current ref_pk and the calibration factor CALF are derived. The graph in Figure 27 shows a three-dimensional representation of the obtained calibration factor for the right sensor 2606. Figure 28 is a graph 2800 showing the reference current signals ref_pk1 and ref_pk2 of sensors 2604 and 2606 as functions of normal distance at various X positions when the Y position is fixed at Y=+40. Utilizing a 2D sensor arrangement, such as that shown in Figures 26A and 26B, any measurement result will provide a reference current value and a corresponding signal measurement value for each sensor. Using this information, the measuring device can determine an appropriate calibration factor to compensate for different distances to the sensors (e.g., normal distance). Additionally, in at least some embodiments, the measuring device can utilize this information to determine the specific X / Y position of the conductor under test. Figure 29 illustrates an example of using the normal distance derived from a reference current signal to determine the position of the conductor under test. In Figure 29, sensor arrangement 2900 is shown as including a left sensor 2902 and a right sensor 2904 arranged in a V-shape. The conductor under test 2910 is shown at position P between sensors 2902 and 2904. As indicated in graph 2800 of Figure 28, the reference current ref_pk can be calculated using the known normal distance. Here, the goal is to derive the normal distance information from the measured reference current signal, which requires the inverse function shown in Figure 28. Because the original functions (ref_pk1 and ref_pk2) are strictly monotonic, a unique inverse function can be determined. The inverse function can then be applied to the measured reference current to obtain the normal distance information. In the example shown, dashed line 2906 indicates the normal distance determined from sensor 2902, and dashed line 2908 indicates the normal distance determined from sensor 2904. The intersection of lines 2906 and 2908 indicates the position P of the conductor 2910 under test. This position can be used for a variety of purposes, including but not limited to determining one or more position-related calibration factors to be applied to the measurement results of electrical parameter measuring equipment, thereby improving its accuracy. For any given point within the V-shaped arrangement of the sensors discussed herein, a reference current value (ref_pk1) for the first sensor and a reference current value (ref_pk2) for the second sensor can be derived. Based on these values, individual calibration factors can be determined by interpolation or by utilizing a previously approximated fitting function or other mathematical formulas. Using two (or more) calibration factors, two (or more) results for the measured value (e.g., voltage) can be calculated. When using more than one sensor, additional V0 results are available, which can be used to calculate an arithmetic mean. In at least some embodiments, the measuring device may utilize a weighted combination of these results, or use only one result if one of the calibration factors is outside a defined range. The weighted combination may be a linear weighted combination, an exponential weighted combination, etc. The weighting value may preferentially consider the highest Iref current equal to the shortest distance from the sensor to the test line, and reduce the more unreliable effects of lower Iref currents, such as due to stray currents, noise, etc. As a non-limiting example, the device may be configured to ignore calibration factors greater than 1.5, since larger calibration factors indicate greater distance and less accurate measurement results. In such examples, useful calibration factors may be determined to be in the range between 1.0 and 1.5, where calibration factors closer to 1.0 are considered better than those closer to 1.5. Therefore, linear weighting or other weighting may be applied such that a weight of 1.0 is applied to calibration factors of 1.0, and a weight of 0.0 is applied to calibration factors of 1.5. For example, weighted measurement results can be derived using the following equation: The formula W(calfX) = 2 × (1.5 - calfX) is used to linearly weight each calibration factor, and the measurement results from the two sensors are Sns1 and Sns2. During implementation, appropriate limits for the calibration factors can be determined using actual calibration data obtained for a specific instrument or instrument type. Figure 30 is a drawing of the front end 3000 of a clamp meter, which includes a first clamping portion 3002 and a second clamping portion 3004 that selectively close to form an opening therebetween. The size and dimensions of this opening are designed to receive a test conductor, such as the exemplary conductors 3008a, 3008b, and 3008c shown in Figure 30. In this example, the front end 3000 includes three “point” sensors 3006a, 3006b, and 3006c that can be used to determine the precise location of the test conductor 3008 and / or to determine one or more calibration factors to be applied to improve the measurement results of the clamp meter. In the illustrated embodiment, sensor 3006 may be relatively small (e.g., 3 × 3 mm), which provides approximately radial variation of the detected signal, rather than the linear variation provided by the linear sensors 2604 and 2606 shown in Figures 26A and 26B. Sensor 3006 may be strategically positioned at a location where the location of the test conductor can be determined most accurately. If the area where the wire is located is mechanically restricted or is limited by a marked area referred to herein as the “optimal point” as discussed further below, an alternative algorithm can be applied to calculate 'a' from all sensors, thus yielding results with less mathematical effort than the multidimensional triangulation calibration discussed above. Using the techniques described above, a reference current signal for each of the sensors 3006a, 3006b, and 3006c can be obtained, and the signal can be processed as described above to determine the X / Y position of the conductor under test. This information can be used for calibration or other purposes. For example, as discussed above, the interpolation process can be used to determine the X / Y position and / or calibration factor using the obtained reference current signal and a previously determined calibration point. Figures 31 through 37 illustrate various techniques for determining the “optimal point” location of a conductor or wire under test, a defined position within the clamp of a clamp instrument where the wire is guided and positioned by a suitable mechanical shape, such as a V-shaped structure. The optimal point location is defined by the center of the wire's diameter circle. Figure 31 is a drawing of the front end 3100 of a clamp meter, which includes a first clamping portion 3102 and a second clamping portion 3104 that selectively close to form an opening therebetween. The size and dimensions of this opening are designed to receive a test conductor, such as the exemplary conductors 3108a, 3108b, and 3108c shown in Figure 31. In this example, the front end 3100 includes three “point” sensors 3106a, 3106b, and 3106c that can be used to determine the precise location of the test conductor 3108 and / or to determine one or more calibration factors to be applied to improve the measurement of the clamp meter. In the illustrated embodiment, sensor 3106 may be relatively small (e.g., 3 × 3 mm), which provides approximately radial variation of the detected signal, rather than the linear variation provided by the linear sensors 2604 and 2606 shown in Figures 26A and 26B. Sensor 3106 may be strategically positioned at a location where the location of the test conductor can be determined most accurately. In at least some embodiments, the sensor 3106a may be located closest to the wire position at the narrow (top) end of the V-shaped front end 3100. The optimal point region is defined by the maximum distance parameter from the sensor. This region delivers a certain level of measurement accuracy and covers lines other than vertical lines and the optimal point location. Optimal point calibration depends on the ability to determine when a wire with an unknown diameter is at its optimal point. Considering a 3D space defined by reference current values ​​from three sensors, the optimal points for various diameters form a curve within this space. The following is a mathematical description of an embodiment of the optimal point algorithm that can be used to implement the algorithm, based on a non-limiting example. In the illustrated embodiment, the calibration method uses three sensors. The region surrounding sensor 3106a (Figure 31) is referred to herein as the optimal point region, and the mechanical guide shape directs the wire to a defined mechanical position, i.e., the “optimal point.” Due to the V-shape of the front end 3100, the wire position depends on the wire diameter, as shown in Figure 31. Due to various factors affecting the reference current (Iref), such as line angles different from the vertical direction, different electrical properties of wire insulation materials (e.g., permittivity), and other environmental influences (e.g., leakage current), the wire position within the optimal point region itself will not always deliver acceptable results. Therefore, the region surrounding the optimal point position must deliver fairly accurate results. The calibration algorithm can be based primarily on different wire diameters located precisely at the optimal point, thus generating different reference currents IR. The reference current IR is limited only by the wire diameter D, since its location is fixed at the optimal point. In at least some implementations, the range of the reference current Iref window value used is typically, for example, between 20,000 and 2,000,000. The full dynamic range of the crest factor CF=2 is 400,000,000 (2^22). For a 14-bit ADC, this is ±8192 = ±2^13, where the fast Fourier transform buffer size is 2^10 = 1024 (5^12 symmetric). Therefore, the absolute maximum window value is 2^13 × 5^12 (2^9) = 2^22. It should be noted that in at least some implementations, the Fast Fourier Transform algorithm employs the Hanning window function, which already includes a normalization factor to provide the result as an RMS value. For visual representation, graph 3200 of Figure 32 shows the transformed coordinate system, which has: X=ln[I ref(sensor 3106c)]-10, Y=ln[I ref(sensor 3106b)]-10 and Z=ln[I ref(sensor 3106a)]-10. ln(20,000) ~ 10 and ln(2,000,000 = 2 21) ~ 14. If we subtract 10, we find the origin (i.e., X = 0, Y = 0, Z = 0). Graph 3200 is presented as a ln X / ln Y / ln Z curve. The point closest to the origin corresponds to the minimum wire diameter (D1.6mm), while the point furthest from the origin corresponds to a diameter of 32mm (D32mm). As a guide, vertical anchor lines (dashed lines) to the ground plane are included at ln(z) = 10. The upper ends of these wires correspond to optimal reference current values ​​(points) for wire diameters from 1.6mm to 32mm. Connections to these optimal calibration points are shown with solid lines. Any instrument reading is represented by three times the reference current (Iref) value, as discussed above, corresponding to another point P in the 3D-ln sensor space. Mathematics allows for the calculation of the shortest distance between this measurement point P and the aforementioned curve (i.e., the solid line between two lines of continuous diameter). This calculation yields two values: the absolute distance d to the curve (the line segment P) and the base point Q along the curve. The shortest distance d is the straight line between points P and Q. Limiting this distance, and requiring the base point to be located close to the linear curve segment, allows for the definition of the optimal point region. It should be noted that the lines constituting the curve segment are infinite. Even if a short distance can be derived, this may not be considered an efficient solution if the base point Q is far outside the defined range of curve points. Due to the special shape of the front end 3100, wires with a diameter greater than 8 mm, such as conductors 3108a and 3108b in Figure 31, are forced to be at a greater distance from sensor 3106a and closer to sensors 3106b and 3106c. Figure 33 shows a graph 3300 of the calibration factor (Y-axis) for the reference current range (X-axis) of sensors 3106a (Cal1), 3106b (Cal2), and 3106c (Cal3). Figure 34 shows a graph 3400 of the calibration factor (Cal1, Y-axis) for sensor 3106a with a reference current range (X-axis) for wires with diameters ranging from 1.6 mm to 32 mm. Figure 35 shows curve 3500, illustrating the calculation of the shortest distance from the test line to the calibration line segment. A suitable distance algorithm uses the left and right sides of the optimal point line segment (artificial extension) 0-1 (as shown in the figure). This length can be optimized using factors between 0 and 1, which are the lengths of the original line segment 0-1 and its extensions on the left and right sides, 1-1 and 1-2, as shown in Figure 35. The extension helps to obtain the shortest distance from the line to the optimal calibration point, such as d1 or d2. Depending on the length of the extension, the suppression from external wires can be controlled, but the optimal point size will also become smaller. The distance parameter DST can be defined as 5 x PQ / OQ, where PQ is the shortest distance from the wire to the curve, and OQ is the distance from the origin to the base point Q (Figure 32). This distance parameter DST is "normalized" for the distance to a wide range of reference current Iref values ​​and can be used as a measure of proximity to the optimal point (in other words, the overall optimal point region). The algorithm is employed and is shown in the curves 3600, 3602, 3604, 3608 and 3610 in Figure 36, where the non-optimal point region is marked with shaded 3614 and no calculation results are provided in this method. The area with shaded 3612 constitutes the output of the actual optimal point calibration algorithm. Readings from all three sensors 3106 are combined with their corresponding calibration factors to produce a weighted overall result. After determining the proximity to the optimal point, the actual calibration value is derived by applying weighting factors to the results from the three sensors. This favors the sensor with the lowest distance (i.e., the highest reference current Iref). To further enhance the advantage of the highest reference current Iref, a squared weighting function can be used: The result in [V] for sensor x is the calibration result for sensors x=1, 2, and 3. W(calfx) = I²refx is the square of the reference current for sensors x=1, 2, and 3. in Where x = 1, 2, 3 For example, for the optimal point method, the outputs at different x / y positions are shown in Table 3700 of Figure 37. The distance factor limit is dd = 2.2. If the distance factor limit dd is greater than this limit, the calset (T6 distance) algorithm can be used instead of the optimal point algorithm, as shown in Table 3700. The signal integration method will now be described with reference to Figures 38 to 40. Figure 38 shows a sensor clamping element input circuit 3800, which includes a transimpedance amplifier and a current integrator to measure the voltage and current in the conductor or cable under test, respectively. As discussed above, the non-contact measurement method based on the formula of the fundamental values ​​is as follows: This formula inherently generates an input current signal multiplied by the frequency due to the capacitive coupling of the signal, which is then converted into a voltage by a transimpedance input amplifier. Additionally, the Rogowski coil coupled to the current integrator generates a current signal with a frequency ratio and a 90° phase shift. Furthermore, due to this analog integrator, the integration of the Rogowski coil can be accomplished using a hard volume integrator to determine the current signal and produce an approximately 90° phase shift relative to the voltage signal, without requiring further calculations to regenerate the original current waveform from the ADC sample. Integrating the voltage signal eliminates scaling with frequency and introduces a similar 90° offset, thus correctly aligning the voltage and current signals again. Due to filtering, the voltage signal can have a small phase shift (e.g., less than 10°), which needs to be compensated for by introducing phase shift interpolation. The following section explains the program that maintains absolute scaling during integration, thus producing a "true" voltage result as the final output. Suppose there is a voltage signal with magnitude parameter A = V sig, incorporating an appropriate voltage scaling based on a normalized 50Hz frequency, in the form: The integral is generated, thereby eliminating the proportionality with frequency as expected: However, the expected result is A˖cos( This is a correctly scaled and phase-shifted signal. Furthermore, we replace numerical integration with a simple summation of a single ADC result, determined by collecting N samples at a frequency of f sample, thus each sample has a “strip width” of 1 / f sample. Other numerical algorithms, such as the Gauss-Legendre quadrature, can be used. in By evaluating the sum indicated above, the resulting integral waveform can be determined as individual points until the desired acquisition point j is: While it can be assumed that for a full-cycle periodic signal, the summation of the sampling points representing the step function is sufficiently accurate to compensate for errors from the rising slope segment on the falling slope segment, this may not be true for partially cycled or aperiodic signals. Therefore, more complex methods can be used to minimize the errors introduced by numerical integration. An exemplary calibration process is discussed below with reference to Figures 39 and 40. The term “calibration” is used herein to refer to conventional calibration relative to an external standard as well as correction for influencing factors. Calibration may involve adjusting the gain correction factor for all input channels to allow a smooth transition from high-sensitivity inputs (i.e., the low voltage range, which is typically 4.2 times more sensitive) to low-sensitivity input channels (the high voltage range). For dual current channels, the difference in sensitivity can typically be around 10 times. In addition, calibration may include adjusting the Vref correction factor to bring the V RMS reading of the reference signal output into agreement with the Vref determined internally by the instrument. Essentially, this is a calibration of the gain network in the Vref signal input path. All voltage readings can then be compared with external absolute voltage measurements based on this calibration. Using the formula described above for the non-contact method, the output value, in addition to the signal frequency discussed further below, also depends on the ratio of Isignal / IREF (IO / IR). Both the reference current IREF and the signal current Isignal change with variations in the diameter of the conductor under test and its distance from the sensor, but for a given voltage, the ratio remains approximately the same. "Approximately" encompasses several influencing factors, such as stray fields and the coverage of the wires on the sensor. Generally, the signal current Isignal decreases faster than the reference current IREF because the latter is particularly "enhanced" by stray fields as the distance increases and the reference current IREF decreases. This can be extensively corrected using a calibration factor table (also referred to herein as the reference current IREF calibration table) to increase the ratio by a specific value depending on the reference current IREF, as discussed elsewhere herein. Figure 39 shows curve 3900, which illustrates the characteristic correlation between the correction factor and the reference current IREF. Frequency can be different factors of interest. Non-contact measurement methods implicitly scale the input signal and frequency, thus resulting in the term fREF / fsignal in the formula. For the purposes of this discussion, the reference frequency fREF can be considered a constant. Dividing the reference frequency by the signal frequency fsignal can be applied in at least two ways: (1) determining the Fast Fourier Transform content (e.g., the sum of squared peaks) of the individual frequency of interest (the fundamental frequency of the signal) and dividing it by the center frequency (fsignal); or (2) normalizing the entire spectrum by multiplying all Fast Fourier Transform windows by the nominal_frequency / window_frequency. The nominal_frequency can be selected (e.g., 50Hz, 60Hz). However, a slight error is introduced due to windowing of the original signal (applying a cosine clock-Henning window function before calculating the Fast Fourier Transform). Suppose we are evaluating a single-frequency signal centered at an arbitrary Fast Fourier Transform window. Following the above discussion, this would require a single normalization using a factor of nominal_frequency / window_frequency. However, windowing causes the signal to appear in adjacent frequency windows at a ratio of approximately 1:2:1. Adjacent windows generated from the same single frequency source will receive different normalization factors based on their respective center window frequencies, contrary to using a single correction factor to handle all components originating from the source signal. The introduced bias depends on the signal frequency associated with the frequency step between windows. For example, with a window spacing of 10 Hz, the frequency difference between adjacent windows totals 1% at a signal frequency of 1000 Hz (adjacent windows at 990 Hz and 1010 Hz), but it increases to a difference of 20% at 50 Hz (adjacent windows at 40 Hz and 60 Hz). Figure 40 is a graph 4000 showing the relative error introduced by RMS summation of appropriately normalized windows in relation to the "single correction factor" method. As shown, at 50 Hz, at the maximum deviation of 20% (for a 10 Hz window difference), the relative error does not exceed 2.1%, as indicated by the dashed line. If the signal frequency is not centered around the window, but falls at 25% of the window interval (e.g., for a 10Hz window interval, it falls at 52.5Hz), a solid line is produced. Slight differences arise from the modified energy distribution within the window and the different applicable normalization factor. This correction can also be applied based on the signal frequency and window interval (which is based on the actual sampling frequency) to mitigate the effects of windowing and uniform normalization of the nominal_frequency / window_frequency. An exemplary calibration procedure involves determining the fundamental signal frequency and evaluating the overall results of the signal and reference values ​​at their respective frequencies, as follows: Vref and fref can be assumed to be constants, where kpkref is the correction factor discussed above. For a single signal frequency, if the received output signal is scaled proportionally to the frequency, then it can be concluded that: As shown above, V'sig essentially depends only on the ratio of pksig / pkref, thus combining all other factors in the constant c. However, we may be interested in transmitting ADC waveform data and need to find a scaling factor such that: Therefore, ADC RMStotal indicates the RMS value of the ADC waveform including the reference frequency. It should be noted that the constant c, in volts (V), characterizes the reference peak "seen" by the instrument. V” sig+ref represents the voltage obtained after considering the signal and reference RMS components. Note that the RMS value can be summed quadratically as: In ADC units, we note the identity (expressed in terms of peak value rather than RMS): The right-hand side represents the RMS sum of the signal and the reference, expressed in volts (V), from which we obtain: This scaling factor depends on pkref, where kpkref also depends on pkref and provides the ADC waveform with a conversion from ADC units to volts, such that: The reference component of the signal, in volts (V), can be easily obtained using the following equation: The following are unrestricted examples of calculations for the following parameters: The foregoing embodiments have illustrated various implementations of the device and / or process using block diagrams, schematic diagrams, and examples. Where such block diagrams, schematic diagrams, and examples contain one or more functions and / or operations, those skilled in the art will understand that each function and / or operation within such block diagrams, flowcharts, or examples can be implemented individually and / or collectively by a wide range of hardware, software, firmware, or virtually any combination thereof. In one embodiment, the subject matter can be implemented using a dedicated integrated circuit (ASIC). However, those skilled in the art will recognize that the embodiments disclosed herein can be equivalently implemented, in whole or in part, in standard integrated circuits to run one or more computer programs on one or more computers (e.g., running one or more programs on one or more computer systems), one or more programs on one or more controllers (e.g., microcontrollers), one or more programs on one or more processors (e.g., microprocessors), firmware, or virtually any combination thereof, and that, in light of this disclosure, designing circuitry and / or writing code for the software and / or firmware will be entirely within the skill of those skilled in the art. Those skilled in the art will recognize that many of the methods or algorithms described herein may employ alternative actions, omit actions, and / or perform actions in a different order than the specified order. Furthermore, those skilled in the art will understand that the mechanisms described herein can be distributed as various forms of program products, and the exemplary embodiments are equally applicable regardless of the specific type of signal-bearing medium used to actually implement the distribution. Examples of signal-bearing media include, but are not limited to, the following: recordable media such as floppy disks, hard disk drives, CD-ROMs, digital magnetic tapes, and computer memory. In view of the foregoing disclosure, various examples of electrical parameter measuring devices may include any or a combination of the following features: a front end including an opening sized and dimensionally designed to receive a conductor under test; a plurality of magnetic field sensors disposed around the opening on a support member; and control circuitry. The plurality of magnetic field sensors includes a first set of equally spaced magnetic field sensors positioned at a first radial distance from the center of the opening, and a second set of equally spaced magnetic field sensors positioned at a second radial distance from the center of the opening. The second radial distance is greater than the first radial distance. Each magnetic field sensor in the first set is radially aligned with a corresponding magnetic field sensor in the second set. The control circuitry is operatively coupled to the plurality of magnetic field sensors. The control circuitry is configured to receive sensor signals from the plurality of magnetic field sensors; determine the physical position of the conductor under test based at least in part on the sensor signals or using mechanical means; and determine the current parameters of the conductor based at least in part on the sensor signals and the physical position. The electrical parameter measuring device may also include another feature, such as determining the physical position of the conductor under test by triangulation of at least three (or exactly three) sensor signals received from at least three (or exactly three) magnetic field sensors. Alternatively, the physical position of the conductor under test may be determined by triangulation of two sensor signals received from two magnetic field sensors. Electrical parameter measuring devices may also include another feature, such as current parameters including alternating current (AC) or direct current (DC). The electrical parameter measuring device may also include another feature, such as each of a plurality of magnetic field sensors including at least one of the following: anisotropic magnetoresistive (AMR) sensor, giant magnetoresistive (GMR) sensor, Hall effect sensor, fluxgate sensor, or coil. Electrical parameter measuring devices may also include another feature, such as control circuitry configured to use sensor signals from exactly two of the magnetic field sensors to determine the physical location of the conductor under test. The electrical parameter measuring device may also include another feature, such as at least one of a plurality of magnetic field sensors including a first sub-sensor and a second sub-sensor arranged at a 90-degree angle relative to the first sub-sensor. The electrical parameter measuring device may also include another feature, such as each of a plurality of magnetic field sensors being formed in an integrated circuit that includes at least one of the other magnetic field sensors. The electrical parameter measuring device may also include another feature, such as each magnetic field sensor in the first group being formed in an integrated circuit having a corresponding radially aligned magnetic field sensor in the second group. The electrical parameter measuring device may also include another feature, such as each magnetic field sensor in the first set of magnetic field sensors being coupled in series with each other, and each magnetic field sensor in the second set of magnetic field sensors being coupled in series with each other. Electrical parameter measuring devices may also include another feature, such as each magnetic field sensor in the magnetic field sensor being individually coupled to the control circuit. The electrical parameter measuring device may also include another feature, such as a third set of equally spaced magnetic field sensors positioned at a third radial distance from the center of the opening, the third radial distance being greater than the second radial distance. Control circuitry is operable to determine that at least one of the magnetic field sensors in the first set is saturated due to the amount of current in the conductor being tested, and to determine the current parameters of the conductor based at least in part on sensor signals from the second and third sets of magnetic field sensors. Electrical parameter measuring devices may also include another feature, such as, in order to determine the current parameters of a conductor, the control circuitry is configured to apply a calibration factor that depends on the physical location of the conductor being tested. The electrical parameter measuring device may also include another feature, such as wherein the control circuit is configured to determine that at least one of the magnetic field sensors is saturated, and to ignore the sensor signal from the at least one magnetic field sensor to determine the current parameters of the conductor under test. The electrical parameter measuring device may also include another feature, such as control circuitry configured to determine that at least one of the magnetic field sensors is saturated, and in response to the determination, to replace the sensor signal of the saturated magnetic field sensor with an interpolated sensor signal obtained using a sensor signal from a magnetic field sensor positioned adjacent to the saturated magnetic field sensor. The electrical parameter measuring device may also include another feature, such as multiple non-contact voltage sensors operatively coupled to a control circuit, wherein the control circuit determines the physical location of the conductor under test based at least in part on sensor signals received from the multiple non-contact voltage sensors. The electrical parameter measuring device may also include another feature, such as control circuitry configured to determine the voltage parameters of the conductor under test based at least in part on sensor signals received from a plurality of non-contact voltage sensors. Electrical parameter measuring devices may also include another feature, such as each of a plurality of magnetic field sensors operating to determine the direction of the magnetic field generated by the conductor under test. Electrical parameter measuring devices may also include another feature, such as control circuitry that applies a unique calibration factor to each of the multiple magnetic field sensors. In view of the foregoing disclosure, various examples of methods for operating an electrical parameter measuring device may include any or a combination of the following features: placing a conductor under test in an opening of a support member of the electrical parameter measuring device, and sensing one or more electrical parameters of the conductor under test. Sensing includes using a plurality of magnetic field sensors, comprising a first set of equally spaced magnetic field sensors positioned at a first radial distance from the center of the opening, and a second set of equally spaced magnetic field sensors positioned at a second radial distance from the center of the opening, the second radial distance being greater than the first radial distance, and each magnetic field sensor in the first set being radially aligned with a corresponding magnetic field sensor in the second set. The method further includes: receiving sensor signals from the plurality of magnetic field sensors; determining the physical position of the conductor under test based at least in part on the sensor signals or mechanical means; and determining a current parameter of the conductor based at least in part on the sensed one or more electrical parameters and the physical position. The method may also include another feature, such as determining the physical location of the conductor under test by using sensor signals from exactly two (or exactly three) of the magnetic field sensors. The method may also include another feature, such as determining the direction of the magnetic field generated by the conductor being tested. The method may also include another feature, such as determining the physical location of the conductor under test by determining the direction of the magnetic field generated by the conductor under test through at least three (or at least two) of a plurality of magnetic field sensors. Other embodiments can be provided by combining the various embodiments described above. In view of the embodiments described above, these and other changes can be made to these embodiments. Generally, the terminology used in the following claims should not be construed as limiting the claims to the embodiments disclosed in this specification and claims, but should be construed as including all possible embodiments and the full scope of the equivalents conferred by these claims. Therefore, the claims are not limited to this disclosure.

[0006] 100: Electrical parameter measuring equipment 102: The conductor under test 104a-h: Sensor 106a-h: Sensor 108: Supporting components 110: Non-magnetic conductor 112: Second conductor 114: Sensor 116: Sensor 200: Components 202: Adder / Integrator 204: Signal 206: Gain adjustment circuit or stage 208: Signal [] 210: Signal conditioning circuit or component 300: Electrical parameter measuring equipment 302: The conductor under test 304a-h: Sensor 306a-h: Sensor 308: Supporting components 311: Slot 314: Central Area 400: Equipment 402: The conductor under test 408: Sensor PCB 410: Base PCB 412: Central Part 414: Internal Sensors 416: External Sensor 600: Integrated Dual Sensors 602: Internal Sensors 604: External Sensor 606: Central Area 700: Integrated Dual Sensors 702: Internal Sensor 704: External Sensor 706: Central Measurement Area 800: Electrical parameter measuring equipment 802: Sensor 804: Sensor 806: The conductor under test 808: Vertical line [] 810: Vertical line 812: Intersection 900: Electrical parameter measuring equipment 902: The conductor under test 904: Internal Sensors 906: External Sensor 908: Supporting Components 910: Slot 914: Central Measurement Area 1000: Electrical parameter measuring equipment 1002a-h: Independent sensor 1004: Measurement Area 1006: Conductor 1008: Circuit 1100: Environment 1102: Non-contact voltage measuring equipment 1104: Operator 1106: Electrical wire 1108: Outer shell 1110:End 1112: Probe Section 1114: User Interface 1116: Recessed portion 1118: First Extension 1120: Second Extension 1122: Conductor 1124: Insulator 1126: Electrode 1128: Grounding part 1130: Common-mode reference voltage source 1132: Grounding protection components 1134: Conductive reference shield 1136: Input Amplifier 1137: Feedback Circuit 1138: Grounding part 1139: Test lead 1140: Signal Processing Module 1142: User Interface 1300: Non-contact voltage measuring equipment 1302: Analog-to-Digital Converter 1306: Fast Fourier Transform 1308: Frame 1310: Digital-to-Analog Converter 1312: Monitor 1500: Calibration System 1502: Calibration of electrical parameter measuring equipment 1504: Control Circuit 1506: Calibrate the voltage source 1508: Calibrate the conductor 1510: Position Control Subsystem 1600: V-shaped front end 1602: Protective components 1604: Conductivity Sensor 1606: Conductivity Sensor 1608: Conductivity Sensor 1610: The conductor under test 1612: Reference Current 1614: Reference Current 1616: Reference Current 1700: V-shaped front end 1702: Protective components 1704: Conductivity Sensor 1706: Conductivity Sensor 1708: The conductor under test 1710: Curve 1712: Curve 1800: V-shaped front end 1802: Protective components 1804: Conductivity Sensor 1806: Conductivity Sensor 1808: The conductor under test 1809: Second position 1810: Curve 1812: Curve 1900: Frontend 1902: Protective components 1904: Sensor 1906: Sensor 1908: The conductor under test 1910: Reference Current Curve 1912: Reference Current Curve 2000: V-shaped front end 2002: Protective components 2004: Conductivity Sensor 2006: Conductivity Sensor 2008: Conductivity Sensor 2010: Tested conductor 2012: Location 2600: Frontend 2602: Protective components 2602a: Left part 2602b: Right part 2604: Conductivity Sensor 2606: Conductivity Sensor 2900: Sensor Arrangement 2902: Sensor 2904: Sensor 2906: Line 2908: Line 2910: The conductor under test 3000: Frontend 3002: First clamping part 3004: Second clamping part 3006a-c: Sensor 3008a-c: Conductor 3100: Frontend 3102: First clamping part 3104: Second clamping part 3106a-c: Sensor 3108a-d: Conductor 3800: Sensor clamping element input circuit

Claims

1. An electrical parameter measuring device, comprising: front end, The front end includes an opening designed in size and dimensions to receive the conductor being tested; A plurality of magnetic field sensors are arranged around the opening, the plurality of magnetic field sensors including a first set of magnetic field sensors positioned at a first radial distance from the center of the opening, and a second set of magnetic field sensors positioned at a second radial distance from the center of the opening, the second radial distance being greater than the first radial distance; and control circuitry operatively coupled to the plurality of magnetic field sensors, the control circuitry being configured to: determine the physical position of the conductor under test based at least in part on a sensing signal received from at least one of the plurality of magnetic field sensors; determine a position-dependent calibration factor based at least in part on the physical position of the conductor under test within the opening at the front end of the electrical parameter measuring device; and apply the position-dependent calibration factor to determine the current parameter of the conductor based at least in part on the physical position of the conductor under test and the sensing signal received from at least one of the plurality of magnetic field sensors.

2. The electrical parameter measuring apparatus as claimed in claim 1, wherein the physical location of the conductor under test is determined by triangulation of signals from at least three sensors received from at least three magnetic field sensors.

3. The electrical parameter measuring device as claimed in claim 1 or 2, wherein at least one of the plurality of magnetic field sensors includes a first sub-sensor and a second sub-sensor, the second sub-sensor being arranged at a 90-degree angle relative to the first sub-sensor.

4. The electrical parameter measuring device as claimed in claim 1 or 2, wherein each of the plurality of magnetic field sensors in the first group is mounted to a support together with a corresponding radially aligned magnetic field sensor in the second group, or wherein each of the plurality of magnetic field sensors in the first group is formed in an integrated circuit including a corresponding magnetic field sensor in the plurality of magnetic field sensors in the second group.

5. The electrical parameter measuring device as claimed in claim 1 or 2, wherein the magnetic field sensors in the first group of magnetic field sensors are coupled in a first series configuration, and the magnetic field sensors in the second group of magnetic field sensors are coupled in a second series configuration.

6. The electrical parameter measuring device as claimed in claim 1 or 2, wherein each magnetic field sensor in the magnetic field sensor is individually coupled to the control circuit.

7. The electrical parameter measuring device as claimed in claim 1 or 2, wherein the plurality of magnetic field sensors includes a third set of magnetic field sensors positioned at a third radial distance from the center of the opening, the third radial distance being greater than the second radial distance, and the control circuitry operates to: determine that at least one of the magnetic field sensors in the first set of magnetic field sensors is saturated due to the amount of current in the conductor under test; and determine the current parameter of the conductor based at least in part on sensor signals from the second set of magnetic field sensors and the third set of magnetic field sensors.

8. The electrical parameter measuring device as claimed in claim 1 or 2, wherein the control circuit is configured to determine that at least one of the plurality of magnetic field sensors is saturated, and to ignore the at least one of the plurality of magnetic field sensors when determining the current parameter of the conductor under test.

9. The electrical parameter measuring device as claimed in claim 1 or 2, wherein the control circuit is configured to identify a saturated magnetic field sensor from the plurality of magnetic field sensors, and to replace the sensor signal of the saturated magnetic field sensor with an interpolated sensor signal obtained using sensor signals from a magnetic field sensor positioned adjacent to the saturated magnetic field sensor.

10. The electrical parameter measuring device as described in claim 1 or 2, further comprising: Multiple non-contact voltage sensors are operatively coupled to the control circuit, wherein the control circuit determines the physical location of the conductor under test based at least in part on sensor signals received from the multiple non-contact voltage sensors.

11. The electrical parameter measuring device as described in claim 1 or 2, wherein: The control circuit applies a unique calibration factor to each of the plurality of magnetic field sensors; or each of the plurality of magnetic field sensors operates to determine the direction of the magnetic field generated by the conductor under test.

12. A method for operating an electrical parameter measuring device, the method comprising: The conductor to be tested is placed in the opening of the support member of the electrical parameter measuring device; The method involves sensing one or more electrical parameters of the conductor under test, wherein the sensing includes using a plurality of magnetic field sensors, the plurality of magnetic field sensors including a first set of magnetic field sensors positioned at a first radial distance from the center of the opening, and a second set of magnetic field sensors positioned at a second radial distance from the center of the opening, the second radial distance being greater than the first radial distance; determining the physical position of the conductor under test within the opening of the support member, wherein the determination is performed at least in part based on a sensor signal received from at least one of the plurality of magnetic field sensors; determining a position-dependent calibration factor at least in part based on the physical position of the conductor under test within the opening of the electrical parameter measuring device; and applying the position-dependent calibration factor to determine the current parameters of the conductor at least in part based on the physical position of the conductor and the sensor signal received from at least one of the plurality of magnetic field sensors.

13. The method of claim 12, wherein determining the physical location of the conductor under test comprises using sensor signals from at least three or exactly three magnetic field sensors.

14. The method of any one of claims 12 and 13, wherein determining the physical location of the conductor under test comprises determining the direction of the magnetic field generated by the conductor under test by at least three of the plurality of magnetic field sensors.

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