Instrument detection method and system based on instrument detection system

Abstract

The present application provides an instrument detection method and system based on an instrument detection system, wherein the instrument detection system includes a device to be detected and a standard device, and the device to be detected is connected to the standard device to form a detection circuit, and during the detection process, a forward measurement is first performed, and then a reverse measurement is performed on at least a portion of the devices in the detection circuit, and then the contact potential difference in the detection circuit is eliminated based on the results of the forward measurement and the reverse measurement. The method and instrument detection system provided by the present application only need to adjust the power supply direction during the detection process, without the need to connect or remove the device multiple times, and the contact potential difference can be eliminated without measuring it, thereby improving the accuracy of error elimination.

Description

Technical Field

[0001] The present application belongs to the field of metrology calibration, and in particular relates to an instrument detection method and system based on an instrument detection system. Background Art

[0002] Instruments and equipment used in the fields of pressure, temperature, process, etc. that send out voltage signals and / or measure voltage signals, such as transmitters, sensors, meters used with sensors or probes, calibrators, etc., must be calibrated before leaving the factory or before use in order to obtain accurate indications in actual use.

[0003] When calibrating the device under test, it is necessary to use wires to electrically connect the device under test with the standard device. Specifically, if the test channel of the device under test is used to emit a voltage signal, it needs to be electrically connected to a standard device with higher measurement accuracy. If the test channel of the device under test is used to measure a voltage signal, it needs to be electrically connected to a standard device that can generate a voltage signal with higher accuracy.

[0004] However, generally speaking, the materials connected to the paths in the equipment under test and the standard equipment are different from the materials of the wires, so a contact potential difference is often formed in the detection circuit. The contact potential difference is the potential difference generated between two different metals at the point where they contact each other in the circuit. Specifically, it is because the electrons in the two different metals have different abilities to cross each other at the interface, resulting in uneven distribution of electrons on both sides of the interface. The side lacking electrons is positively charged, and the side with excess electrons is negatively charged. When dynamic equilibrium is reached, the potential difference established at the metal interface is the contact potential difference.

[0005] For example, when the voltage signal generated by the channel under test is transmitted to the standard device, the actual voltage U S As shown in the following formula I:

[0006] U S =U T +Δu L Formula I

[0007] Among them, U S Indicates the actual voltage on standard equipment, U T Indicates the actual voltage at the detected channel, Δu L Represents the contact potential difference. Generally, Δu L It is much smaller than the scale value of the channel being tested and can be ignored. However, in the field of micro-electric voltage detection, since the voltage signal being measured is small, higher accuracy is required. For example, the range is only 0-10mV, Δu L It may reach the scale value of the channel being tested, so Δu Lcannot be ignored, especially in the field of metrology and calibration, where the requirements for measurement accuracy are relatively high. L The resulting deviations need to be compensated.

[0008] There is a solution in the prior art. Before the device to be tested is connected to the detection circuit, a calibration standard device with the same function as the device to be tested is first connected to the detection circuit to form a detection circuit with the original standard device, thereby L Direct measurement is performed. After the measurement is completed, the calibration standard equipment is removed, and the device under test is connected to the detection circuit. Then, according to the above Δu L The measurement result compensates the actual measured indication of the device under test. However, since this solution requires testing the calibration standard equipment once and then testing the device under test again, it will not only double the test volume, but also require switching between the standard equipment and the device under test. In particular, for batch testing of hundreds of instruments to be tested, this solution is difficult to achieve automated operation, which seriously restricts the detection speed. Summary of the invention

[0009] In order to solve the problems existing in the prior art, the present application provides an instrument detection method and system based on an instrument detection system, wherein the instrument detection system includes a main control system and at least one detection circuit, the detection circuit includes a standard device and is connected to a device to be detected, and the main control system controls the standard device and the device to be detected to perform at least two rounds of detection, wherein in the first round of detection, a signal generating device applies a first signal to the detection circuit, and a signal measuring device detects the first signal to obtain a first measurement result, the signal generating device is any one of the standard device and the device to be detected, and the signal measuring device is the other of the standard device and the device to be detected; in the second round of detection, the signal generating device applies a second signal to the detection circuit, and the signal measuring device detects the second signal to obtain a second measurement result, and the second signal is opposite to the first signal; based on the first signal, the first measurement result, the second signal and the second measurement result, the contact potential difference is calculated, and then the test result of the device to be detected is corrected, and the method can realize automatic detection of the contact potential difference of the device to be detected in the detection circuit, without introducing a standard inspection device, simplifying the operation, and saving a lot of time cost in the process of detecting a large number of devices to be detected.

[0010] The purpose of this application is to provide the following aspects:

[0011] In a first aspect, the present application provides an instrument detection method based on an instrument detection system, the instrument detection system comprising a main control system and at least one detection circuit, the detection circuit comprising a first standard device, the first standard device comprising a first signal generating device or a first signal measuring device, the instrument detection system being used to detect a first detected device, the first detected device comprising the first signal generating device or the other of the first signal measuring devices, the instrument detection method comprising: controlling the first signal generating device to apply a first electrical signal to the detection circuit, the first signal measuring device measuring the first electrical signal, obtaining a first measurement result, and sending the first measurement result to the main control system; controlling the first signal generating device to apply a second electrical signal to the detection circuit, the first signal measuring device measuring the second electrical signal, obtaining a second measurement result, and sending the second measurement result to the main control system, wherein the second electrical signal is opposite to the first electrical signal; the main control system calculates a contact potential difference of the detection circuit according to the first measurement result and the second measurement result; the main control system detects the first detected device based on the detection circuit, obtains a first detection result, and compensates the first detection result according to the contact potential difference.

[0012] The method provided by the present application applies two electrical signals of opposite directions in the detection circuit, and obtains a measurement result for each electrical signal. Ideally, the difference between the two measurement results is twice the contact potential difference. After determining the contact potential difference, the device under test can be tested according to the test task to obtain the test result, and then the test result is corrected according to the contact potential difference, thereby achieving online acquisition of the contact potential difference of the device under test in the detection circuit without the additional introduction of inspection standard equipment. On the one hand, it greatly simplifies the operation of determining the contact potential difference, and on the other hand, it can also avoid the error introduced by the difference between the inspection standard equipment and the device under test. It can be understood that the steps of testing the device under test and determining the contact potential difference can be interchanged, that is, the device under test can be tested according to the test task first, and after the test, the contact potential difference of the device under test in the detection circuit can be determined according to the method provided by the present application.

[0013] In combination with the instrument detection method described in the first aspect, the controlling the first signal generating device to apply the first electrical signal to the detection circuit includes: controlling the first signal generating device to be positively connected to the detection circuit, and the first signal generating device generates the first electrical signal; the controlling the first signal generating device to apply the second electrical signal to the detection circuit includes: controlling the first signal generating device to be reversely connected to the detection circuit, and the first signal generating device generates the first electrical signal.

[0014] In the present application, by switching the connection direction, the first signal generating device can generate the same electrical signal without introducing signal errors, and an opposite electrical signal can pass through the detection circuit, thereby further improving the measurement accuracy of the contact potential difference.

[0015] In combination with the instrument detection method described in the first aspect, the control of the first signal measuring device to measure the first electrical signal includes: controlling the first signal measuring device to be positively connected to the detection circuit, and the first signal measuring device measures the electrical signal transmitted by the detection circuit; the first signal measuring device to measure the second electrical signal includes: controlling the first signal measuring device to be reversely connected to the detection circuit, and the first signal measuring device measures the electrical signal transmitted by the detection circuit.

[0016] In the present application, by switching the connection direction, on the one hand, an opposite electrical signal actually passes through the detection circuit, which facilitates eliminating the influence of the signal itself in the calculation; on the other hand, the electrical signal actually measured by the first signal measuring device is very close and will not introduce signal errors, thereby further improving the measurement accuracy of the contact potential difference.

[0017] In combination with the instrument detection method described in the first aspect, the first standard device includes the first signal generating device and the second signal measuring device, the instrument detection system is also used to detect the second detected device, the second detected device includes the second signal generating device, and the instrument detection method also includes: controlling the second detected device to be positively connected to the detection circuit, the second detected device generates a third electrical signal, controlling the first detected device to be positively connected to the detection circuit, the first detected device measures the electrical signal transmitted by the detection circuit, obtains a third measurement result, and sends the third measurement result to the main control system, the third electrical signal is the same as the first electrical signal; controlling the second detected device to be reversely connected to the detection circuit, the second detected device generates the third electrical signal, controlling the first detected device to be positively connected to the detection circuit, the first detected device measures the electrical signal transmitted by the detection circuit , obtain a fourth measurement result, and send the fourth measurement result to the main control system; control the second device under test to be positively connected to the detection circuit, the second device under test generates the third electrical signal, the first standard device measures the electrical signal transmitted by the detection circuit, obtains a fifth measurement result, and sends the fifth measurement result to the main control system; control the second device under test to be reversely connected to the detection circuit, the second device under test generates the third electrical signal, the first standard device measures the electrical signal transmitted by the detection circuit, obtains a sixth measurement result, and sends the sixth measurement result to the main control system; the main control system calculates the contact potential difference of the detection circuit according to the first electrical signal, the second electrical signal, the third electrical signal, the first measurement result, the second measurement result, the third measurement result, the fourth measurement result, the fifth measurement result, and the sixth measurement result.

[0018] In the present application, for the case where the first signal generating device and the first signal measuring device cannot be reversed connected to the detection circuit, if the first device to be detected is a signal measuring device, the contact potential difference between any two devices in the detection circuit can be determined by introducing a second standard device (signal measuring device) that can be reversed connected to the detection circuit, thereby determining the contact potential difference of the device to be detected in the detection circuit.

[0019] In combination with the instrument detection method described in the first aspect, the first standard device includes the first signal measuring device and the third signal generating device, the instrument detection system is also used to detect the third detected device, and the third detected device includes a third signal measuring device. The instrument detection method also includes: controlling the first detected device to be positively connected to the detection circuit, the first detected device generates a fourth electrical signal, controlling the third detected device to be positively connected to the detection circuit, the third detected device measures the electrical signal transmitted by the detection circuit, obtains a seventh measurement result, and sends the seventh measurement result to the main control system, the fourth electrical signal is the same as the first electrical signal; controlling the first detected device to be positively connected to the detection circuit, the first detected device generates a fifth electrical signal, controlling the third detected device to be reversely connected to the detection circuit, the third detected device measures the electrical signal transmitted by the detection circuit, obtains an eighth measurement result, and sends the eighth measurement result to the main control system. measurement result, wherein the fifth electrical signal is the same as the second electrical signal; controlling the first standard device to apply the fourth electrical signal to the detection circuit, controlling the third device to be detected to be positively connected to the detection circuit, the third device to be detected to measure the electrical signal transmitted by the detection circuit, obtaining a ninth measurement result, and sending the ninth measurement result to the main control system; controlling the first standard device to apply the fifth electrical signal to the detection circuit, controlling the third device to be detected to be reversely connected to the detection circuit, the third device to be detected to measure the electrical signal transmitted by the detection circuit, obtaining a tenth measurement result, and sending the tenth measurement result to the main control system; the main control system calculates the contact potential difference of the detection circuit according to the first electrical signal, the second electrical signal, the fourth electrical signal, the fifth electrical signal, the first measurement result, the second measurement result, the seventh measurement result, the eighth measurement result, the ninth measurement result and the tenth measurement result.

[0020] In the present application, for the case where the first signal generating device and the first signal measuring device cannot be reversely connected to the detection circuit, if the first device to be detected is a signal generating device, the contact potential difference between any two devices in the detection circuit can be determined by introducing a third standard device (signal generating device) that can be reversely connected to the detection circuit, thereby determining the contact potential difference of the device to be detected in the detection circuit.

[0021] In combination with the instrument detection method described in the first aspect, the first device under test is detected based on the detection circuit, including: determining at least one first detection point based on the first device under test; controlling the first signal generating device to apply an electrical signal to the detection circuit according to the first detection point; the first signal measuring device measures the electrical signal of the detection circuit to obtain the first detection result; and detecting the first device under test based on the compensated first detection result and the first detection point.

[0022] In combination with the instrument detection method described in the first aspect, the first standard device is the first signal generating device, the instrument detection system is also used to detect a fourth device under test, and the fourth device under test is a signal generating device. The instrument detection method also includes: the detection of the first device under test includes determining that the first device under test has a first allowable error; determining at least one second detection point based on the fourth device under test, the second detection point is within the measuring range of the fourth device under test and the first device under test, and the allowable error of the fourth device under test is greater than the first allowable error; the first standard device applies an electrical signal to the detection circuit according to the second detection point, the first device under test measures the electrical signal of the detection circuit, obtains a second detection result, and sends the second detection result to the main control system; the fourth device under test applies an electrical signal to the detection circuit according to the second detection point, the first device under test measures the electrical signal of the detection circuit, obtains a third detection result, and sends the third detection result to the main control system; the fourth device under test is detected based on the second detection point, the second detection result and the third detection result.

[0023] In the present application, during batch testing of multiple devices under test, the devices under test (signal generating devices) under test in the same batch can be used to assist in determining the contact potential difference of the first device under test (signal measuring device) in the detection circuit.

[0024] In combination with the instrument detection method described in the first aspect, the first standard device is the first signal measuring device, and the instrument detection system is also used to detect a fifth device under test, and the fifth device under test is a signal measuring device. The instrument detection method also includes: the detection of the first device under test includes determining that the first device under test has a first allowable error; determining at least one third detection point based on the fifth device under test, the third detection point is within the measuring range of the fifth device under test and the first device under test, and the allowable error of the fifth device under test is greater than the first allowable error; the first device under test applies an electrical signal to the detection circuit according to the third detection point, the first standard device measures the electrical signal of the detection circuit, obtains a fourth detection result, and sends the fourth detection result to the main control system; the first device under test applies an electrical signal to the detection circuit according to the third detection point, the fifth device under test measures the electrical signal of the detection circuit, obtains a fifth detection result, and sends the fifth detection result to the main control system; the fifth device under test is detected based on the three detection points, the fourth detection result and the fifth detection result.

[0025] In the present application, during batch testing of multiple devices under test, the devices under test (signal measuring devices) tested in the same batch can be used to assist in determining the contact potential difference of the first device under test (signal generating device) in the detection circuit.

[0026] In a second aspect, the present application further provides a computer-readable storage medium, on which computer instructions are stored, and when the instructions are executed by a processor, the steps of the instrument detection method described in the first aspect are implemented.

[0027] In a third aspect, the present application also provides an instrument detection device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the instrument detection method described in the first aspect above.

[0028] In a fourth aspect, the present application also provides a main control system, which is applied to an instrument detection system, and the main control system is configured to send a first generation control signal to a first signal generating device, and send a first connection control signal to a detection circuit, so that the first signal generating device is electrically connected to the detection circuit and applies a first electrical signal to the detection circuit, and the first signal generating device is one of a first standard device or a first device to be inspected; at least partially simultaneously with the first generation control signal and the first connection control signal, send a first measurement control signal to a first signal measuring device, and send a second connection control signal to the detection circuit, so that the first signal measuring device is electrically connected to the detection circuit, and measures the first electrical signal transmitted by the detection circuit to generate a first measurement result, and the first signal measuring device is another one of the first standard device or the first device to be inspected; send a second generation control signal to the first signal generating device, and send a second connection control signal to the detection circuit, so that the first signal measuring device is electrically connected to the detection circuit, and measures the first electrical signal transmitted by the detection circuit to generate a first measurement result. three connection control signals, so that the first signal generating device is electrically connected to the detection circuit and applies a second electric signal to the detection circuit, wherein the second electric signal is opposite to the first electric signal; at least partially simultaneously with the second generating control signal and the third connection control signal, a second measurement control signal is sent to the first signal measuring device, and a fourth connection control signal is sent to the detection circuit, so that the first signal measuring device is electrically connected to the detection circuit and measures the second electric signal transmitted by the detection circuit to generate a second measurement result; the first measurement result and the second measurement result are obtained from the first signal measuring device; the contact potential difference of the detection circuit is calculated based on the first measurement result and the second measurement result; the contact potential difference is stored, a first detection result is obtained, and the first detection result is compensated for according to the contact potential difference, wherein the first detection result is measurement information generated based on the detection of the first device under test by the detection circuit.

[0029] In a fifth aspect, the present application also provides an instrument detection system, the instrument detection system includes a detection circuit, the detection circuit includes a first standard device, the first standard device is any one of a first signal generating device or a first signal measuring device, the instrument detection system is used to detect a first device to be detected, the first device to be detected is the other of the first signal generating device or the first signal measuring device, in at least one measurement process, the detection circuit is electrically connected to the first signal generating device and the first signal measuring device, so that the first signal generating device applies a first electrical signal to the detection circuit, and the first signal measuring device measures the first electrical signal to generate a first measurement result; in at least another measurement process, the detection circuit is electrically connected to the first signal generating device and the first signal measuring device, so that the first signal generating device applies a second electrical signal to the detection circuit, and the first signal measuring device measures the second electrical signal to generate a second measurement result, and the first measurement result and the second measurement result are used to calculate the contact potential difference of the detection circuit; in at least one detection process, the detection circuit is electrically connected to the first standard device and the first device to be detected, used to detect the first device to be detected and generate a first detection result, and the contact potential difference is used to compensate for the first detection result.

[0030] Compared with the prior art, the instrument detection system provided by the present application includes a device to be detected and a standard device, such as a standard voltmeter, a standard ammeter, etc., and the device to be detected is connected to the standard device to form a detection circuit. The method provided by the present application first performs a forward measurement on the device to be detected during the detection process, and then performs a reverse measurement on at least a part of the devices in the detection circuit, including the device to be detected and / or the standard device, and then eliminates the contact potential difference in the detection circuit according to the results of the forward measurement and the reverse measurement, thereby obtaining a more accurate detection result. The method and instrument detection system provided by the present application only need to change the power supply direction during the detection process, without the need to connect or remove the device multiple times, reducing the complexity of the operation, and the contact potential difference can be eliminated without measuring it, thereby improving the accuracy of error elimination. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a detection circuit is shown;

[0032] Figure 2 A flow chart of a method for eliminating detection line errors provided by the present application is shown. DETAILED DESCRIPTION

[0033] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of methods consistent with some aspects of the present invention as detailed in the appended claims.

[0034] The method for eliminating detection line errors and the instrument detection system provided by the present application are described in detail below through specific embodiments.

[0035] First, a brief introduction to the usage scenarios of this solution is given.

[0036] According to different functions, instrumentation equipment can be divided into at least two categories: one is used to generate signals, specifically voltage signals or current signals, which are called signal generating equipment; the other is used to measure signals, specifically voltage values ​​or current values, which are called signal measuring equipment.

[0037] According to the different roles in the detection process, instrumentation equipment can be divided into at least two categories: one is the detection object, called the device under test, or the instrument under test; the other is used to provide standard values, called standard equipment.

[0038] It can be understood that the device under test can be either a signal generating device or a signal measuring device. Similarly, the standard device can be either a signal generating device or a signal measuring device.

[0039] Usually, the functions of the device under test and the standard device are different, so after determining the contact potential difference between the device under test and the detection circuit, the test result of the device under test can be directly corrected.

[0040] In the present application, according to the general understanding of those skilled in the art, there is a corresponding relationship between the standard device and the device under test. Specifically, the standard device has higher accuracy. Compared with the standard device, the device under test has lower accuracy. Therefore, it can be considered that the indication of the standard device is the true value. The standard device can at least cover part of the range of the device under test. Taking the standard device as a signal generating device and the device under test as a signal measuring device as an example, the range of the signal generated by the standard device is 1 to 5 mV, and the measurement range of the device under test is 0 to 3 mV, so that the standard device can generate a standard signal for detecting the device under test or measure the signal under test generated by the device under test.

[0041] Corresponding to the standard equipment, it is considered that the tested equipment itself has a systematic error, that is, it has a relatively low accuracy. For the convenience of description, in the following examples, it is assumed that the tested equipment has a systematic error Δu T Moreover, the system error value of the device under test cannot be determined before the device under test is calibrated.

[0042] In the present application, it is assumed that the system error existing in the detected device has a good linear change.

[0043] A few standard devices have both functions, that is, they can generate standard signals and can also be used for standard measurements. However, in the case of a passage, only a single function is enabled, that is, only one of the two functions can be enabled, but not both at the same time.

[0044] Figure 1 A schematic diagram showing the instrument detection system used in this application is shown as follows: Figure 1 As shown, the instrument detection system includes a main control system and at least one detection circuit. The main control system is used to control each device in the detection circuit and can also process the test results of the detected device connected to the detection circuit.

[0045] Typically, the detection circuit is used to connect the device under test and the corresponding standard device. During batch testing, since there are multiple devices under test and the types of the devices under test may be different, there may also be multiple standard devices. These standard devices and the devices under test can be connected by the same detection circuit. Accordingly, a switching switch / on-off switch or similar device will be configured in the detection circuit, so that at a certain moment, only one signal generating device and one signal measuring device are started in the detection circuit.

[0046] It is understandable that the detection circuit also includes necessary components to form the circuit, such as signal lines and power lines, etc. In the present application, the signal lines are used to transmit signals between the main control system and each device, including control signals and data signals, etc., and the power lines are used to provide power to each device.

[0047] In the present application, the contact potential difference in the detection circuit is generated based on the material of the connection line, and its direction does not change with the change of the current direction.

[0048] The present application is intended to solve the inherent deviation factor of the contact potential difference detection circuit. Therefore, the present application mainly describes how to measure and eliminate the contact potential difference. This does not mean that the present application excludes other technical means for solving measurement errors. In fact, the solution of the present application can be combined with other methods for solving measurement errors in the prior art. For example, if a solution is designed in the prior art to solve the signal deviation caused by impedance, since impedance and contact potential difference are different deviation factors, the prior art solution can be combined with the present application, that is, it is allowed to use multiple compensation values ​​to compensate for the measurement results, thereby making the measurement results more reliable.

[0049] In addition, it should be noted that in the present application, the detection circuit includes at least the following two uses: the first is to determine the contact potential difference of the device under test in the detection circuit; the second is to test the device under test according to the test task configured for the device under test.

[0050] In this application, the standard equipment has the following characteristics: the standard equipment is generally tested and verified by more advanced standard equipment, so its measurement results have higher credibility and can be considered as true values. At the same time, from the perspective of metrology and detection, the accuracy of the standard equipment is generally higher than the accuracy of the tested equipment, that is, the allowable error of the standard equipment is smaller than the allowable error of the tested equipment. In some cases, the allowable error of the standard equipment is 1 / 2, 1 / 3, 1 / 4 or even smaller than the allowable error of the tested equipment.

[0051] In the present application, signal generating equipment, that is, equipment that can generate electrical signals, includes but is not limited to calibrators, process instruments, transmitters, sensors, signal standards, etc., and signal measuring equipment, that is, equipment that can measure electrical signals, includes but is not limited to calibrators, process instruments, (measuring instrument) heads, etc.

[0052] Figure 2 The present application provides a flow chart of an instrument detection method based on an instrument detection system. In this example, the detection circuit includes a first standard device, which is either a first signal generating device or a first signal measuring device. The instrument detection system is used to detect a first detected device, which is either the first signal generating device or the first signal measuring device. That is, if the first standard device is a first signal generating device, the first detected device is a first signal measuring device. On the contrary, if the first standard device is a first signal measuring device, the first detected device is a first signal generating device. Figure 2 As shown, the method includes the following steps S001 to S004:

[0053] Step S001: Control the first signal generating device to apply a first electrical signal to the detection circuit, and the first signal measuring device to measure the first electrical signal, obtain a first measurement result, and send the first measurement result to the main control system.

[0054] In this example, the first electrical signal is an electrical signal that matches the first device under test. Specifically, if the first device under test is a voltage generating or voltage measuring device, the first electrical signal is a voltage signal; if the first device under test is a current generating or current measuring device, the first electrical signal is a current signal.

[0055] In the present application, the term "apply" refers to providing an electrical signal to the detection circuit so that for the first signal generating device, it can, within its capability, make the value of the electrical signal passing through the detection circuit equal to the target electrical signal value. If the first signal generating device is a standard device, theoretically the electrical signal it generates is equal to the target electrical signal value (it is exactly the opposite in the case of reverse connection). If the first electrical signal generating device is the device under test, due to the errors in the device under test itself, the application at this time is just the electrical signal that the device under test thinks it has generated the target electrical signal value, but in fact this electrical signal may deviate from the true value. In addition, due to factors such as contact potential difference, the signal value of the electrical signal applied by the signal generating device may deviate from the signal value it generates after passing through the detection circuit.

[0056] It can be understood that the first electrical signal is within the measuring range of the first standard device and the first tested device.

[0057] In this example, the first measurement result is a result of the first electrical signal being acted upon by the contact potential difference.

[0058] Step S002, control the first signal generating device to apply a second electrical signal to the detection circuit, the first signal measuring device measures the second electrical signal, obtains a second measurement result, and sends the second measurement result to the main control system, wherein the second electrical signal is opposite to the first electrical signal.

[0059] In this example, the second electrical signal and the first electrical signal have the same value but opposite directions.

[0060] In this example, the second measurement result is a result of the second electrical signal acting on the contact potential difference.

[0061] In this example, the contact potential difference acting on the second telecommunication signal and the contact potential difference acting on the first electrical signal have the same direction and are equal in value.

[0062] In this example, applying the second electrical signal can be achieved in a variety of different ways, for example, by reversely connecting the first signal generating device to the detection circuit, etc. Specifically, it can be achieved as shown in other subsequent embodiments.

[0063] Step S003: The main control system calculates the contact potential difference of the detection circuit according to the first measurement result and the second measurement result.

[0064] In this example, the electrical signal forming the first measurement result and the electrical signal forming the second measurement result are of the same magnitude and opposite direction, and are mathematically expressed as opposite numbers, while the contact potential difference in the secondary measurement is equal in magnitude and the same direction, and is mathematically expressed as equal numbers. Based on this, the contact potential difference can be calculated by mathematical methods.

[0065] Step S004: the main control system detects the first detected device based on the detection circuit to obtain a first detection result, and compensates the first detection result according to the contact potential difference.

[0066] In this example, detection is performed according to the test task corresponding to the first device, and the obtained test result is also affected by the contact potential difference. Therefore, the contact potential difference can be compensated according to the contact potential difference determined by steps S101 to S103, so that the test result is more accurate.

[0067] It can be understood that the method for compensating the test result in this step can adopt any method for compensating the test result of the device under test in the prior art.

[0068] It can be understood that the contact potential difference can be compensated to the measurement result obtained by the signal measuring device, and can also be compensated to the signal generated by the signal generating device. Generally, the contact potential difference is compensated to the signal generating device.

[0069] The method provided by the present application applies two electrical signals of opposite directions in the detection circuit, and obtains a measurement result for each electrical signal. Ideally, the difference between the two measurement results is twice the contact potential difference. After determining the contact potential difference, the device under test can be tested according to the test task to obtain the test result, and then the test result is corrected according to the contact potential difference, thereby achieving online acquisition of the contact potential difference of the device under test in the detection circuit without the additional introduction of inspection standard equipment. On the one hand, it greatly simplifies the operation of determining the contact potential difference, and on the other hand, it can also avoid the error introduced by the difference between the inspection standard equipment and the device under test. It can be understood that the steps of testing the device under test and determining the contact potential difference can be interchanged, that is, the device under test can be tested according to the test task first, and after the test, the contact potential difference of the device under test in the detection circuit can be determined according to the method provided by the present application.

[0070] If the first signal generating device can be reversely connected to the detection circuit, the solution of the present application can be as shown in the following embodiment 1 and embodiment 2.

[0071] Embodiment 1

[0072] In this embodiment, a method for measuring the contact potential difference is given through S101 - S103 .

[0073] The first signal generating device is the first standard device, and the first signal measuring device is the first device to be detected, and the first standard device can be switched to be connected in a forward or reverse manner in the detection circuit for use, then:

[0074] In step S101, the first signal generating device applies the first electrical signal to the detection circuit, which specifically can be: the first standard device is directly connected to the detection circuit and generates the first electrical signal.

[0075] Specifically, the relationship between the first measurement result and the first electrical signal satisfies the following formula 1-1:

[0076] U N11 +Δu L1 =U R11 +Δu T11 Formula 1-1

[0077] Among them, U N11 Indicates the standard indication of the standard voltage generated by the first standard device in this step, that is, the first electrical signal;

[0078] Δu L1 represents the contact potential difference of the detection circuit connecting the first standard device and the first device under test;

[0079] U R11 represents an actual indication of the first device under test, that is, the first measurement result;

[0080] Δu T11 Indicates the measurement error of the first device under test when measuring the first electrical signal.

[0081] In this embodiment, in step S102, the first signal generating device applies the second electrical signal to the detection circuit, specifically: the first standard device is reversely connected to the detection circuit and generates the first electrical signal.

[0082] Specifically, the relationship between the second measurement result and the second electrical signal satisfies the following formula 1-2:

[0083] -U N11 +Δu L1 =U R12 +Δu T12 Formula 1-2

[0084] Among them, U N11 Indicates the standard value of the standard voltage generated by the standard device in this step, that is, the first electrical signal, so -U N11 That is, the second electrical signal;

[0085] Δu L1 represents the contact potential difference of the first detected device in the detection circuit, which is the same as that in Formula 1-1 because the connection line remains unchanged;

[0086] U R12 represents the actual indication of the device under test, that is, the second measurement result;

[0087] Δu T12 Indicates the measurement error of the first device under test when measuring the second electrical signal.

[0088] Furthermore, when the first device under test is relatively stable, its measurement error is uniformly distributed, that is, Δu T12 With Δu T11 The relationship satisfies the following equations 1-3:

[0089] Δu T11 =-Δu T12 Formula 1-3

[0090] In step S103, the above formula 1-1 is added to formula 1-2 to obtain:

[0091] U N11 +Δu L1 -U N11 +Δu L1 =U R11+Δu T11 +U R12 +Δu T12 Formula 1-4

[0092] Further processing the above formula 1-4 in combination with the above formula 1-3 can obtain the following formula 1-5:

[0093]

[0094] It can be understood that, in this embodiment, the measurement order of applying the forward signal S101 and applying the reverse signal S102 can be swapped.

[0095] Embodiment 2

[0096] This embodiment has the same equipment basis as that of the first embodiment, the first signal generating device is the first standard device, and the first signal measuring device is the first device to be tested. The difference from the first embodiment is that, further, the first device to be tested can be switchably connected in the detection circuit in positive and reverse connection. Therefore, this embodiment can solve technical problems independently of the first embodiment, or can be combined with the first embodiment to solve technical problems together. Taking the joint solution of technical problems as an example, a method for measuring contact potential difference is given by further improving S201-S203.

[0097] The first signal generating device is the first standard device, and the first signal measuring device is the first device to be detected, and the first standard device can be reversely connected to the detection circuit for use, then:

[0098] Step S201 , the first signal generating device applies the first electrical signal to the detection circuit, which may specifically be: the first standard device is directly connected to the detection circuit and generates the first electrical signal.

[0099] This embodiment also includes that the first signal measuring device measures the first electrical signal, which may be specifically: the first device under test is positively connected to the detection circuit and measures the first electrical signal.

[0100] Specifically, the relationship between the first measurement result and the first electrical signal satisfies Formula 2-1:

[0101] U N11 +Δu L1 =U R11 +Δu T11 Formula 2-1

[0102] Among them, U N11 Indicates the standard indication of the standard voltage generated by the first standard device in this step, that is, the first electrical signal;

[0103] ΔuL1 represents the contact potential difference of the detection circuit connecting the first standard device and the first device under test;

[0104] U R11 represents an actual indication of the first device under test, that is, the first measurement result;

[0105] Δu T11 Indicates the measurement error of the first device under test when measuring the first electrical signal.

[0106] Step S202, the first signal generating device applies the second electrical signal to the detection circuit, which may specifically be: the first standard device is reversely connected to the detection circuit and generates the first electrical signal.

[0107] Specifically, the relationship between the second measurement result and the second electrical signal satisfies the following formula 2-2:

[0108] -U N11 +Δu L1 =-(U R12 +Δu T12 ) Formula 2-2

[0109] Among them, U N11 Indicates the standard value of the standard voltage generated by the standard device in this step, that is, the first electrical signal, so -U N11 That is, the second electrical signal;

[0110] Δu L1 represents the contact potential difference of the first detected device in the detection circuit, which is the same as that in Formula 1-1 because the connection line remains unchanged;

[0111] U R12 represents the actual indication of the device under test, that is, the second measurement result;

[0112] Δu T12 Indicates the measurement error of the first device under test when measuring the second electrical signal.

[0113] Furthermore, U R11 and U R12 Both are measurements of the first electrical signal. Due to the existence of the contact potential difference, the two have a very small difference. At the same or similar measurement points, the system error of the first device under test remains unchanged, that is, Δu T12 With Δu T11 The relationship satisfies the following formula 2-3:

[0114] Δu T11 =Δu T12 Formula 2-3

[0115] Step S203, adding the above formula 2-1 and formula 2-3 to obtain:

[0116] U N11 +Δu L1 -U N11 +Δu L1 =U R11 +Δu T11 -U R12 -Δu T12 Formula 2-4

[0117] Further processing of the above formula 2-4 can obtain the following formula 2-5:

[0118]

[0119] It can be understood that, in this embodiment, the measurement order of the forward measurement S201 and the reverse measurement S202 can be swapped.

[0120] Embodiment 3

[0121] In this embodiment, a method for measuring the contact potential difference is provided through S301 - S303 .

[0122] The first signal generating device is the first device under test, and the first signal measuring device is the first standard device, and the first device under test can be reversely connected to the detection circuit for use, then:

[0123] In step S301, the first signal generating device applies the first electrical signal to the detection circuit, which specifically includes: the first detected device is directly connected to the detection circuit and generates the first electrical signal.

[0124] Specifically, the relationship between the first measurement result and the first electrical signal satisfies the following formula 3-1:

[0125] U R11 +Δu T11 +Δu L1 =U N11 Formula 3-1

[0126] Among them, U R11 Indicates the indication of the electrical signal generated by the first device under test in this step, that is, the first electrical signal;

[0127] Δu L1 represents the contact potential difference of the detection circuit connecting the first device under test and the first standard device;

[0128] U N11 Indicates that the first standard equipment detects U R11 the actual indication of , i.e., the first measurement result;

[0129] ΔuT11 It represents the system error of the first device under test when generating the first electrical signal.

[0130] In this embodiment, in step S302, the first signal generating device applies the second electrical signal to the detection circuit by: the first detected device is reversely connected to the detection circuit and generates the first electrical signal.

[0131] Specifically, the relationship between the second measurement result and the second electrical signal satisfies the following formula 3-2:

[0132] -(U R12 +Δu T12 )+Δu L1 =U N12 Formula 3-2

[0133] Among them, U R12 Indicates the indication of the electrical signal generated by the first device under test in this step, that is, the first electrical signal;

[0134] U N12 Indicates the first standard equipment detection U R22 the actual indication of , that is, the second measurement result;

[0135] Δu L1 represents the contact potential difference of the detection circuit connecting the first device under test and the first standard device;

[0136] Δu T12 It represents the system error of the first device under test when generating the second electrical signal.

[0137] Furthermore, U R11 and U R12 are all values ​​of the first electrical signal. Since the generated signals are the same, the system error of the first device under test remains unchanged, Δu T11 With Δu T12 The relationship satisfies the following formula 3-3:

[0138] Δu T11 =Δu T12 Formula 3-3

[0139] In step S303, the above formula 3-1 is added to formula 3-2 to obtain:

[0140] U R11 +Δu T11 -U R12 -Δu T12 +Δu L1 +Δu L1 =U N11 +U N12 Formula 3-4

[0141] By processing the above formula 3-4 in combination with the above formula 3-3, the following formula 3-5 can be obtained:

[0142]

[0143] It can be understood that, in this embodiment, the measurement order of the forward measurement and the reverse measurement can be swapped.

[0144] In the present application, for a first signal generating device that can be reversely connected to the detection circuit, no matter the first signal generating device is the first standard device or the first device to be detected, the first signal generating device can be reversely connected to the detection circuit to apply a second signal opposite to the first signal to the detection circuit, thereby simplifying the operation of determining the contact potential difference to the greatest extent.

[0145] Embodiment 4

[0146] This embodiment has the same equipment basis as that of the third embodiment, the first signal generating device is the first device to be tested, and the first signal measuring device is the first standard device. The difference from the third embodiment is that, further, the first device to be tested can be switchably connected in the detection circuit in positive and reverse connection, so the first standard device can be reversely connected in the detection circuit. Therefore, this embodiment can solve technical problems independently of the third embodiment, or can be combined with the third embodiment to solve technical problems together. Taking the joint solution of technical problems as an example, the method of measuring contact potential difference by implementing this embodiment alone is given below through S401-S403.

[0147] In step S401, the first signal measuring device measures the first electrical signal by: the first standard device is connected to the detection circuit and measures the first electrical signal.

[0148] Specifically, the relationship between the first measurement result and the first electrical signal satisfies the following formula 4-1:

[0149] U R11 +Δu T11 +Δu L1 =U N11 Formula 4-1

[0150] Among them, U R11 An indication of a voltage signal generated by the first device under test, that is, the first electrical signal;

[0151] Δu T11 Indicates a system error when the first detected device corresponds to the first electrical signal;

[0152] Δu L1represents the contact potential difference of the first detected device in the detection circuit;

[0153] U N11 It indicates that during the forward measurement process, the first standard device detects the indication of the voltage signal, that is, the first measurement result.

[0154] In step S402, the first signal measuring device measuring the second electrical signal may specifically include: the first standard device is reversely connected to the detection circuit and measures the second electrical signal.

[0155] Specifically, the relationship between the second measurement result and the second electrical signal satisfies the following formula 4-2:

[0156] (U R12 +Δu T12 )+Δu L1 =-U N12 Formula 4-2

[0157] Among them, U R12 An indication of a voltage signal generated by the first device under test, that is, the second electrical signal;

[0158] Δu T12 Indicates the system error of the first detected device when it corresponds to the second electrical signal;

[0159] Δu L1 represents the contact potential difference of the first detected device in the detection circuit;

[0160] U N12 It represents the standard indication obtained by the first standard device during the reverse measurement process, that is, the second measurement result.

[0161] As mentioned above, in this embodiment, U R11 with U R12 The relationship satisfies the following formula 4-3:

[0162] U R11 =-U R12 Formula 4-3

[0163] Furthermore, when the first device under test is relatively stable, its measurement error is uniformly distributed, Δu T11 With Δu T12 The relationship satisfies the following formula 4-4:

[0164] Δu T11 =-Δu T12 Formula 4-4

[0165] In S403 of this embodiment, the above formula 4-3 and formula 4-4 are combined, and the above formula 4-1 and formula 4-2 are added and subtracted respectively to obtain the following formula 4-5:

[0166]

[0167] In this embodiment, if the voltage signal generated by the device under test is the target voltage value, the standard indication value (U R41 +Δu T41 ), the difference between the standard indication and the indication under test is the system error of the equipment under test.

[0168] If the voltage signal generated by the device under test is not the target voltage value, the contact potential difference Δu of the test circuit can be calculated according to formula 4-5. L1 ,Furthermore, when the standard equipment subsequently detects the target voltage, it can calculate the difference between the indication of the standard measuring instrument and the contact potential difference, thereby obtaining the true value of the voltage signal generated by the tested equipment.

[0169] It is understandable that, in an actual detection process, if both the first signal generating device and the first signal measuring device can be reversely connected to the detection circuit, any one of Embodiments 1 to 4 can be selected for execution according to actual needs.

[0170] In the actual detection process, based on the above-mentioned embodiments one and four, if the first device under test is not allowed to be reversely connected to the detection circuit, in this case, the present application can use the second device under test to help determine the contact potential difference between any two devices in the detection circuit, thereby determining the contact potential difference between the first device under test and the first standard device in the detection circuit, wherein the first standard device should have both a signal generating device and a signal measuring device, and the second device under test and the first device under test are respectively a signal generating device and a signal measuring device.

[0171] In this case, the solution of the present application may be as shown in the following Embodiment 5 and Embodiment 6.

[0172] Embodiment 5

[0173] In this embodiment, the first standard device includes a first signal generating device and a signal measuring device, and the first detected devices are all first signal measuring devices. The contact potential difference between any two devices in the detection circuit is determined by means of the second detected device, so as to determine the contact potential difference of the first detected device in the detection circuit, wherein the second detected device is also a signal generating device, and specifically includes the following steps S501 to S507:

[0174] For the convenience of describing the process of S501-S507, for the case where the standard device is reversely connected to the detection circuit, if it is connected in the right way and the corresponding signal is still within the standard signal range, the standard device can also be connected in the right way.

[0175] Step S501, the first standard device is connected to the detection circuit and generates a first electrical signal, the first detected device is connected to the detection circuit and measures, a first measurement result is obtained, and the first measurement result is sent to the main control system;

[0176] Specifically, the relationship between the first measurement result and the first electrical signal satisfies the following formula 5-1:

[0177] U N11 +Δu L1 =U R11 +Δu T11 Formula 5-1

[0178] Among them, U R11 Indicates the indication of the first device under test;

[0179] Δu T11 Indicates the error of the first device under test in this measurement;

[0180] Δu L1 represents the contact potential difference of the detection circuit between the first standard device and the first device under test;

[0181] U N11 Indicates the signal value of the first standard device, that is, the first electrical signal.

[0182] Step S502, the first standard device is reversely connected to the detection circuit, the first standard device generates a first electrical signal, the first device under test is forwardly connected to the detection circuit and measures, a second measurement result is obtained, and the second measurement result is sent to the main control system;

[0183] Specifically, the relationship between the first measurement result and the first electrical signal satisfies the following formula 5-2:

[0184] -U N12 +Δu L1 =U R12 +Δu T12 Formula 5-2

[0185] Among them, U R12 Indicates the indication of the first device under test;

[0186] Δu T12 Indicates the error of the first device under test in this measurement;

[0187] ΔuL1 represents the contact potential difference, which is the same as in Equation 5-1;

[0188] U N12 Indicates the signal value of the first standard device, that is, the first electrical signal.

[0189] Step S503: the second device under test is connected to the detection circuit and generates a third electrical signal, the first device under test is connected to the detection circuit and measures, obtains a third measurement result, and sends the third measurement result to the main control system, and the third electrical signal is the same as the first electrical signal.

[0190] Specifically, the relationship between the third measurement result and the third electrical signal satisfies the following formula 5-3:

[0191] U R21 +Δu T21 +Δu L2 =U R13 +Δu T13 Formula 5-3

[0192] Among them, U R21 A signal indicating a value of a second device under test, that is, a first electrical signal;

[0193] Δu T21 Indicates the error of the second device under test in this measurement;

[0194] Δu L2 represents the contact potential difference of the detection circuit between the second device under test and the first device under test;

[0195] U R13 Indicates the indication of the first device under test;

[0196] Δu T13 Indicates the error of the first device under test in this measurement, due to U R13 and U R11 is very close, so Δu T13 =Δu T11 .

[0197] Step S504: the second device under test is reversely connected to the detection circuit and generates the third electrical signal, the first device under test is forwardly connected to the detection circuit and measures, a fourth measurement result is obtained, and the fourth measurement result is sent to the main control system.

[0198] Specifically, the relationship between the fourth measurement result and the third electrical signal satisfies the following formula 5-4:

[0199] -(U R21 +Δu T21 )+Δu L2 =UR14 +Δu T14 Formula 5-4

[0200] Among them, U R21 Indicates the signal indication of the second device under test, which is the same as formula 5-3;

[0201] Δu T21 It represents the error of the second device under test in this measurement. Since the second device under test corresponds to the same main signal in the two measurements, it is the same as formula 5-3.

[0202] Δu L2 represents the contact potential difference, which is the same as in Equation 5-3;

[0203] U R14 Indicates the indication of the first device under test;

[0204] Δu T14 Indicates the error of the first device under test in this measurement. Since the first device under test in this measurement and the measurement in S502 correspond to very close main signals, Δu T14 and Δu T12 same.

[0205] Step S505: the second device under test is connected to the detection circuit and generates a fourth electrical signal. The first standard device performs measurement to obtain a fifth measurement result, and sends the fifth measurement result to the main control system. The fourth electrical signal is the same as the first electrical signal.

[0206] Specifically, the relationship between the fifth measurement result and the fourth electrical signal satisfies the following formula 5-5:

[0207] U R21 +Δu T21 +Δu L3 =U N15 Formula 5-5

[0208] Among them, U R21 Indicates the signal indication of the second device under test, which is the same as formula 5-3;

[0209] Δu T21 It represents the error of the second device under test in this measurement, which is the same as formula 5-3;

[0210] Δu L3 represents the contact potential difference of the detection circuit between the second device under test and the first standard device;

[0211] U N15 It represents the measurement result of the first standard device, that is, the fifth measurement result.

[0212] Step S506: the second detected device is reversely connected to the detection circuit and generates the fourth electrical signal; the second standard device performs measurement to obtain a sixth measurement result, and sends the sixth measurement result to the main control system.

[0213] Specifically, the relationship between the sixth measurement result and the fourth electrical signal satisfies the following formula 5-6:

[0214] -(U R21 +Δu T21 )+Δu L3 =U N16 Formula 5-6

[0215] Among them, U R21 Indicates the signal indication of the second device under test, which is the same as formula 5-3;

[0216] Δu T21 It represents the error of the second device under test in this measurement, which is the same as formula 5-3;

[0217] Δu L3 represents the contact potential difference, which is the same as in Equation 5-5;

[0218] U N16 It represents the measurement result of the first standard device, that is, the sixth measurement result.

[0219] Step S507: The main control system calculates the contact potential difference of the detection circuit according to the first electrical signal, the second electrical signal, the third electrical signal, the fourth electrical signal, the first measurement result, the second measurement result, the third measurement result, the fourth measurement result, the fifth measurement result, and the sixth measurement result.

[0220] Furthermore, for the first device under test and the second device under test, since both are connected by connecting the detection circuit to be tested, for the same detection system, different detection circuit materials are generally not additionally configured. Therefore, the contact potential difference of the detection circuits between the two will cancel each other out due to the symmetry of the connection structure, that is, Δu can be ignored. L2 .

[0221] The above S501-S506 obtains six equations, corresponding to Δu L1 , Δu L3 , Δu T11 =Δu T13 , Δu T12 =Δu T14 and Δu T21 There are five unknowns. Since the number of unknowns is less than the number of equations, the value of the contact potential difference can be obtained by solving the equations, that is, the value of the contact potential difference of the detection circuit. For example, as shown in the following equations 5-7 and 5-8:

[0222]

[0223]

[0224] Embodiment 6

[0225] In this embodiment, the first standard device includes a first signal measuring device and a signal generating device, the first inspected device is a signal generating device, and the accuracy of the first inspected device is lower than the accuracy of the first standard device. The instrument detection system is also used to detect a third inspected device, and the third inspected device is a signal measuring device, and its detection accuracy is lower than the detection accuracy of the first standard device.

[0226] In this embodiment, the instrument detection method further includes the following steps S601 to S607:

[0227] Step S601: the first device under test is connected to the detection circuit and generates a fifth electrical signal, the third device under test is connected to the detection circuit and measures, obtains a seventh measurement result, and sends the seventh measurement result to the main control system, and the fifth electrical signal is the same as the first electrical signal.

[0228] Specifically, the relationship between the seventh measurement result and the fifth electrical signal satisfies the following formula 6-1:

[0229] U R11 +Δu T11 +Δu L1 =U R31 +Δu T31 Formula 6-1

[0230] Among them, U R11 Indicates the value of the voltage generated by the first device under test in this step, that is, the first electrical signal;

[0231] Δu L1 represents the contact potential difference between the first detected device and the third detected device in the detection circuit;

[0232] U R31 represents the actual indication of the third device under test, that is, the seventh measurement result;

[0233] Δu T11 represents the systematic error of the first device under test;

[0234] Δu T31 Indicates the systematic error of the third device under test.

[0235] Step S602: The first device under test is positively connected to the detection circuit and generates a sixth electrical signal, the third device under test is reversely connected to the detection circuit and measures, obtains an eighth measurement result, and sends the eighth measurement result to the main control system, wherein the sixth electrical signal is the same as the second electrical signal.

[0236] Specifically, the relationship between the eighth measurement result and the sixth electrical signal satisfies the following formula 6-2:

[0237] U R12 +Δu T12 +Δu L1 =-(U R32 +Δu T32 ) Formula 6-2

[0238] Among them, U R12 Indicates the value of the voltage generated by the first device under test in this step, that is, the second electrical signal;

[0239] Δu L1 represents the contact potential difference, which is the same as formula 6-1;

[0240] U R32 represents the actual indication of the third device under test, that is, the eighth measurement result;

[0241] Δu T12 represents the systematic error of the first device under test;

[0242] Δu T32 Indicates the system error of the third device under test, due to U R32 and U R31 is very close, so Δu T32 Equal to Δu T31 .

[0243] Step S603: the first standard device applies the fifth electrical signal to the detection circuit, the third device under test is connected to the detection circuit and measures, obtains a ninth measurement result, and sends the ninth measurement result to the main control system.

[0244] Specifically, the relationship between the ninth measurement result and the fifth electrical signal satisfies the following formula 6-3:

[0245] U N11 +Δu L2 =U R33 +Δu T33 Formula 6-3

[0246] Among them, U N11 represents the value of the electrical signal output by the first standard device, that is, the first electrical signal;

[0247] ΔuL2 represents the contact potential difference of the detection circuit between the first standard device and the third device under test;

[0248] U R33 represents the actual indication of the third device under test, that is, the ninth measurement result;

[0249] Δu T33 Indicates the system error of the third device under test, due to U R33 and U R31 is very close, so Δu T33 Equal to Δu T31 .

[0250] Step S604: the first standard device applies the sixth electrical signal to the detection circuit, the third device under test is reversely connected to the detection circuit and measures, a tenth measurement result is obtained, and the tenth measurement result is sent to the main control system.

[0251] Specifically, the relationship between the tenth measurement result and the sixth electrical signal satisfies the following formula 6-4:

[0252] U N12 +Δu L2 =-(U R34 +Δu T34 ) Formula 6-4

[0253] Among them, U N12 represents the value of the electrical signal output by the first standard device, that is, the second electrical signal;

[0254] Δu L2 represents the contact potential difference of the detection circuit between the first standard device and the third device under test;

[0255] U R34 represents the actual indication of the third device under test, that is, the ninth measurement result;

[0256] Δu T34 Indicates the system error of the third device under test, due to U R34 and U R31 is very close, so Δu T34 Equal to Δu T31 .

[0257] Step S605: the first device under test is connected to the detection circuit to apply the first electrical signal, and the first standard device performs measurement to obtain a first measurement result that satisfies the following formula 6-5:

[0258] U R13 +Δu T13 +Δu L3 =U N11Formula 6-5

[0259] Among them, U N11 Represents the measurement indication of the first standard device, that is, the first measurement result;

[0260] Δu L3 represents the contact potential difference of the detection circuit between the first device under test and the first standard device;

[0261] U R13 represents an actual indication of the first detected device, that is, the first electrical signal;

[0262] Δu T13 Represents the system error of the first device under test, due to U R13 and U R11 is very close, so Δu T13 Equal to Δu T11 .

[0263] Step S606: the first device under test is connected to the detection circuit to apply the second electrical signal, and the first standard device performs measurement to obtain a second measurement result that satisfies the following formula 6-6:

[0264] U R14 +Δu T14 +Δu L3 =U N12 Formula 6-6

[0265] Among them, U N12 Indicates the measurement indication of the first standard device, i.e., the second measurement result;

[0266] Δu L3 represents the contact potential difference of the detection circuit between the first device under test and the first standard device;

[0267] U R14 represents the actual indication of the first device under test, that is, the second electrical signal;

[0268] Δu T14 Represents the system error of the first device under test, due to U R14 and U R12 is very close, so Δu T14 Equal to Δu T12 .

[0269] Step S607: The main control system calculates the contact potential difference of the detection circuit according to the first electrical signal, the second electrical signal, the fifth electrical signal, the sixth electrical signal, the first measurement result, the second measurement result, the seventh measurement result, the eighth measurement result, the ninth measurement result and the tenth measurement result.

[0270] Furthermore, for the first device under test and the third device under test, since both are connected by connecting the detection circuit to be tested, for the same detection system, different detection circuit materials are generally not additionally configured. Therefore, the contact potential difference between the detection circuits of the two will cancel each other out due to the symmetry of the connection structure.

[0271] The above S601-S606 obtain six equations, corresponding to five unknowns. Since the number of unknowns is less than the number of equations, the value of the contact potential difference can be obtained by solving the equations, that is, the value of the contact potential difference of the detection circuit, as shown in the following equations 6-7 and 6-8:

[0272]

[0273]

[0274] It is understandable that the order of step S601 to step S606 in this embodiment can be changed.

[0275] In the present application, the devices under test in the same batch may also be used to assist in determining the contact potential difference of the first device under test in the detection circuit, as shown in the following seventh and eighth embodiments.

[0276] Embodiment 7

[0277] In this embodiment, if the first standard device is a first signal generating device, and another fourth device to be tested, which is also a signal generating device, needs to be tested, since a detection signal is transmitted in the detection circuit at the same time, the first standard device and the fourth device to be tested cannot be measured at the same time. This embodiment provides a solution.

[0278] First, a first device under test is detected based on the detection circuit, including: determining at least one first detection point based on the first device under test; controlling the first signal generating device to apply an electrical signal to the detection circuit according to the first detection point; measuring the electrical signal of the detection circuit by the first signal measuring device to obtain the first detection result; and detecting the first device under test based on the compensated first detection result and the first detection point to determine that the first device under test has a first allowable error.

[0279] Based on the above process, it can be understood that the first device under test is first tested and it is determined that the measured error of the first device under test is less than or equal to the first allowable error, thereby determining the accuracy of the first device under test at least within a shorter period of time.

[0280] Afterwards, the fourth device under test is tested using the first device under test, including:

[0281] First, at least one second detection point is determined based on the fourth device under inspection, wherein the second detection point is within the measuring range of the fourth device under inspection and the first device under inspection, and the allowable error of the fourth device under inspection is greater than the first allowable error; in this way, the first device under inspection can meet the temporary inspection requirements for the fourth device under inspection.

[0282] There may be one or more second detection points, and for each second detection point, two detection processes are performed.

[0283] One of the detection processes, the first standard device applies an electrical signal to the detection circuit according to the second detection point, the first detected device measures the electrical signal of the detection circuit, obtains a second detection result, and sends the second detection result to the main control system;

[0284] In the second detection process, the fourth detected device applies an electrical signal to the detection circuit according to the second detection point, the first detected device measures the electrical signal of the detection circuit, obtains a third detection result, and sends the third detection result to the main control system.

[0285] Based on one of the aforementioned detection processes and the second detection process, two sets of detection data with corresponding relationships can be obtained, one set of detection data includes a standard electrical signal (derived from the first standard device) and a second detection result (derived from the first device under test), and the other set of detection data includes a detected signal (derived from the fourth device under test) and a third detection result (derived from the first device under test).

[0286] Subsequent processing can include:

[0287] The fourth detected device is detected based on the second detection point, the second detection result, and the third detection result.

[0288] Specifically, since the second detection result and the third detection result are derived from the same device under test and correspond to almost the same signal value, the detection errors contained in the second detection result and the third detection result are the same. Based on this, the second detection result can be used to evaluate or compensate for the third detection result. The evaluation method includes, based on the second detection result and the standard electrical signal (that is, the second detection point), determining whether the difference between the two meets the aforementioned first allowable error. If so, the second detection point and the third detection result can be directly output as detection data for the fourth device under test. The compensation method includes, calculating the deviation between the second detection result and the second detection point, thereby determining the deviation of the first device under test at the second detection point, and then compensating the deviation into the third detection result, and detecting the fourth device under test based on the compensated third detection result and the second detection point.

[0289] Embodiment 8

[0290] In this embodiment, if the first standard device is a first signal measuring device, and another fifth device to be tested, which is also a signal measuring device, needs to be tested, since a detection signal is transmitted in the detection circuit at the same time, the first standard device and the fifth device to be tested cannot be measured at the same time. This embodiment provides a solution.

[0291] First, a first device under test is detected based on the detection circuit, including: determining at least one first detection point based on the first device under test; controlling the first signal generating device to apply an electrical signal to the detection circuit according to the first detection point; measuring the electrical signal of the detection circuit by the first signal measuring device to obtain the first detection result; and detecting the first device under test based on the compensated first detection result and the first detection point to determine that the first device under test has a first allowable error.

[0292] Afterwards, the fifth device under test is tested using the first device under test, including:

[0293] First, at least one third detection point is determined based on the fifth inspected device, wherein the third detection point is within the measuring range of the fifth inspected device and the first inspected device, and the allowable error of the fifth inspected device is greater than the first allowable error; in this way, the first inspected device can meet the temporary inspection requirements for the fifth inspected device.

[0294] There may be one or more third detection points, and for each third detection point, two detection processes are performed.

[0295] One of the detection processes, the first detected device applies an electrical signal to the detection circuit according to the third detection point, the first standard device measures the electrical signal of the detection circuit, obtains a fourth detection result, and sends the fourth detection result to the main control system;

[0296] In a second detection process, the first detected device applies an electrical signal to the detection circuit according to the third detection point, the fifth detected device measures the electrical signal of the detection circuit, obtains a fifth detection result, and sends the fifth detection result to the main control system;

[0297] Based on one of the aforementioned detection processes and the second detection process, two sets of detection data with corresponding relationships can be obtained, one set of detection data includes a detected electrical signal (derived from the first detected device) and a standard measurement result (the fourth detection result, derived from the first standard device), and the other set of detection data includes a detected electrical signal (also derived from the first detected device) and a fifth detection result (derived from the fourth detected device).

[0298] Subsequent processing can include:

[0299] The fifth detected device is detected based on the third detection point, the fourth detection result and the fifth detection result.

[0300] Specifically, since the electrical signals under test of the two sets of detection data originate from the same device under test and correspond to almost the same signal values, the signal errors in the two sets of electrical signals under test are the same. Based on this, the fourth detection result can be used to evaluate or compensate for the fifth detection result. The evaluation method includes, based on the electrical signal under test (that is, the third detection point) and the fourth detection result, determining whether the difference between the two meets the aforementioned first allowable error. If so, the third detection point and the fifth detection result can be directly output as detection data for the fourth device under test. The compensation method includes, calculating the deviation between the fourth detection result and the third detection point, thereby determining the deviation of the first device under test at the third detection point, and then compensating the deviation to the third detection point, and detecting the fifth device under test based on the compensated third detection point and the fifth detection result.

[0301] In addition, the present application also provides a computer-readable storage medium, on which computer instructions are stored. When the instructions are executed by a processor, the steps of the instrument detection method described in the first aspect above are implemented.

[0302] In addition, the present application also provides an instrument detection device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the instrument detection method described in the first aspect above.

[0303] In addition, the present application also provides a main control system, which is applied to an instrument detection system, and the main control system is configured to send a first generation instruction to a first signal generating device, the first generation instruction is used to instruct the first signal generating device to apply a first electrical signal to the detection circuit; send a first measurement instruction to a first signal measuring device, the first measurement instruction is used to instruct the first signal measuring device to measure the first electrical signal and obtain a first measurement result; send a second generation instruction to the first signal generating device, the second generation instruction is used to instruct the first signal generating device to apply a second electrical signal to the detection circuit, and the second electrical signal is opposite to the first electrical signal; send a second measurement instruction to the first signal measuring device, the second measurement instruction is used to instruct the first signal measuring device to measure the second electrical signal and obtain a second measurement result; calculate the contact potential difference of the detection circuit according to the first measurement result and the second measurement result; send a third generation instruction to the first signal generating device, send a third measurement instruction to the first signal measuring device, obtain a first detection result, and compensate the first detection result according to the contact potential difference. The first detected device is either the first signal generating device or the first signal measuring device, and the other of the first signal generating device or the first signal measuring device is a standard device.

[0304] In another case, the main control system is applied to an instrument detection system, and the main control system is configured to send a first generation control signal to a first signal generating device, and send a first connection control signal to a detection circuit, so that the first signal generating device is electrically connected to the detection circuit and applies a first electrical signal to the detection circuit, and the first signal generating device is one of a first standard device or a first device to be detected; at least partially simultaneously with the first generation control signal and the first connection control signal, send a first measurement control signal to a first signal measuring device, and send a second connection control signal to the detection circuit, so that the first signal measuring device is electrically connected to the detection circuit and measures the first electrical signal transmitted by the detection circuit to generate a first measurement result, and the first signal measuring device is the other of the first standard device or the first device to be detected; send a second generation control signal to the first signal generating device, and send a third connection control signal to the detection circuit. signal, so that the first signal generating device is electrically connected to the detection circuit and applies a second electrical signal to the detection circuit, wherein the second electrical signal is opposite to the first electrical signal; at least partially simultaneously with the second generating control signal and the third connecting control signal, a second measuring control signal is sent to the first signal measuring device, and a fourth connecting control signal is sent to the detection circuit, so that the first signal measuring device is electrically connected to the detection circuit and measures the second electrical signal transmitted by the detection circuit to generate a second measurement result; the first measurement result and the second measurement result are obtained from the first signal measuring device; the contact potential difference of the detection circuit is calculated based on the first measurement result and the second measurement result; the contact potential difference is stored, a first detection result is obtained, and the first detection result is compensated for according to the contact potential difference, wherein the first detection result is measurement information generated based on the detection of the first device under test by the detection circuit.

[0305] In addition, the present application also provides an instrument detection system, which includes a detection circuit, and the detection circuit includes a first standard device, the first standard device is either a first signal generating device or a first signal measuring device, the instrument detection system is used to detect a first device to be detected, the first device to be detected is the other of the first signal generating device or the first signal measuring device, the first signal generating device is used to apply a first electrical signal to the detection circuit; the first signal measuring device is used to measure the first electrical signal to obtain a first measurement result, and send the first measurement result to the main control system; the first signal generating device is also used to apply a second electrical signal to the detection circuit, and the second electrical signal is opposite to the first electrical signal; the first signal measuring device is also used to measure the second electrical signal to obtain a second measurement result, and send the second measurement result to the main control system, so that the main control system calculates the contact potential difference of the detection circuit according to the first measurement result and the second measurement result, and compensates the first detection result according to the contact potential difference, and the first detection result is a detection result obtained by detecting the first device to be detected based on the detection circuit.

[0306] In another case, the instrument detection system includes a detection circuit, the detection circuit includes a first standard device, the first standard device is one of a first signal generating device or a first signal measuring device, the instrument detection system is used to detect a first device to be detected, the first device to be detected is the other of the first signal generating device or the first signal measuring device; in at least one measurement process, the detection circuit is electrically connected to the first signal generating device and the first signal measuring device, so that the first signal generating device applies a first electrical signal to the detection circuit, and the first signal measuring device measures the first electrical signal to generate a first measurement result; in at least another measurement process, the detection circuit is electrically connected to the first signal generating device and the first signal measuring device, so that the first signal generating device applies a second electrical signal to the detection circuit, and the first signal measuring device measures the second electrical signal to generate a second measurement result, and the first measurement result and the second measurement result are used to calculate the contact potential difference of the detection circuit; in at least one detection process, the detection circuit is electrically connected to the first standard device and the first device to be detected, and is used to detect the first device to be detected and generate a first detection result, and the contact potential difference is used to compensate for the first detection result.

[0307] The description is not to be construed as a limitation of the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, various equivalent substitutions, modifications or improvements may be made to the technical solution and implementation methods of the present application, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. An instrument detection method based on an instrument detection system, characterized in that: The instrument detection system includes a main control system and at least one detection circuit, the detection circuit includes a first standard device and a first detected device, the first standard device includes a first signal generating device or a first signal measuring device, the instrument detection system is used to detect the first detected device, the first detected device includes the first signal generating device or the first signal measuring device, and the instrument detection method includes: Controlling the first signal generating device to apply a first electrical signal to the detection circuit, and the first signal measuring device to measure the first electrical signal, obtain a first measurement result, and send the first measurement result to the main control system; Controlling the first signal generating device to apply a second electrical signal to the detection circuit, the first signal measuring device to measure the second electrical signal, obtain a second measurement result, and send the second measurement result to the main control system, wherein the first signal generating device is controlled to switch the connection direction in the detection circuit, or the first signal measuring device is controlled to switch the connection direction in the detection circuit, the second electrical signal is equal to the first electrical signal in value and opposite in direction; The main control system calculates the contact potential difference of the detection circuit according to the first measurement result and the second measurement result; The main control system detects the first detected device based on the detection circuit to obtain a first detection result, and compensates the first detection result according to the contact potential difference.

2. The instrument detection method according to claim 1, characterized in that: The controlling the first signal generating device to apply the first electrical signal to the detection circuit comprises: controlling the first signal generating device to be connected to the detection circuit, so that the first signal generating device generates the first electrical signal; The controlling the first signal generating device to apply the second electrical signal to the detection circuit includes: controlling the first signal generating device to be reversely connected to the detection circuit, so that the first signal generating device generates the first electrical signal.

3. The instrument detection method according to claim 1, characterized in that: The controlling the first signal measuring device to measure the first electrical signal comprises: controlling the first signal measuring device to be connected to the detection circuit, so that the first signal measuring device measures the electrical signal transmitted by the detection circuit; The first signal measuring device measures the second electrical signal, including: controlling the first signal measuring device to be reversely connected to the detection circuit, and the first signal measuring device measures the electrical signal transmitted by the detection circuit.

4. The instrument detection method according to claim 1 or 2, characterized in that: The first standard device includes the first signal generating device and the second signal measuring device, the instrument detection system is further used to detect a second detected device, the second detected device includes a second signal generating device, and the instrument detection method further includes: Control the second device under test to be connected to the detection circuit, so that the second device under test generates a third electrical signal; control the first device under test to be connected to the detection circuit, so that the first device under test measures the electrical signal transmitted by the detection circuit, obtains a third measurement result, and sends the third measurement result to the main control system, wherein the third electrical signal is the same as the first electrical signal; Control the second device under test to be reversely connected to the detection circuit, so that the second device under test generates the third electrical signal; control the first device under test to be forwardly connected to the detection circuit, so that the first device under test measures the electrical signal transmitted by the detection circuit, obtains a fourth measurement result, and sends the fourth measurement result to the main control system; Controlling the second device under test to be positively connected to the detection circuit, so that the second device under test generates the third electrical signal, the first standard device measures the electrical signal transmitted by the detection circuit, obtains a fifth measurement result, and sends the fifth measurement result to the main control system; Control the second device under test to be reversely connected to the detection circuit, so that the second device under test generates the third electrical signal, the first standard device measures the electrical signal transmitted by the detection circuit, obtains a sixth measurement result, and sends the sixth measurement result to the main control system; The main control system calculates the contact potential difference of the detection circuit according to the first electrical signal, the second electrical signal, the third electrical signal, the first measurement result, the second measurement result, the third measurement result, the fourth measurement result, the fifth measurement result, and the sixth measurement result.

5. The instrument detection method according to claim 1 or 3, characterized in that: The first standard device includes the first signal measuring device and a third signal generating device, the instrument detection system is further used to detect a third detected device, the third detected device includes a third signal measuring device, and the instrument detection method further includes: Controlling the first device under test to be connected to the detection circuit, so that the first device under test generates a fourth electrical signal; controlling the third device under test to be connected to the detection circuit, so that the third device under test measures the electrical signal transmitted by the detection circuit, obtains a seventh measurement result, and sends the seventh measurement result to the main control system, wherein the fourth electrical signal is the same as the first electrical signal; Control the first device under test to be positively connected to the detection circuit, so that the first device under test generates a fifth electrical signal, control the third device under test to be reversely connected to the detection circuit, so that the third device under test measures the electrical signal transmitted by the detection circuit, obtains an eighth measurement result, and sends the eighth measurement result to the main control system, wherein the fifth electrical signal is the same as the second electrical signal; Controlling the first standard device to apply the fourth electrical signal to the detection circuit, controlling the third device under test to be connected to the detection circuit, the third device under test to measure the electrical signal transmitted by the detection circuit, obtaining a ninth measurement result, and sending the ninth measurement result to the main control system; Control the first standard device to apply the fifth electrical signal to the detection circuit, control the third device under test to be reversely connected to the detection circuit, the third device under test to measure the electrical signal transmitted by the detection circuit, obtain a tenth measurement result, and send the tenth measurement result to the main control system; The main control system calculates the contact potential difference of the detection circuit based on the first electrical signal, the second electrical signal, the fourth electrical signal, the fifth electrical signal, the first measurement result, the second measurement result, the seventh measurement result, the eighth measurement result, the ninth measurement result and the tenth measurement result.

6. The instrument detection method according to any one of claims 1 to 3, characterized in that: Detecting the first detected device based on the detection circuit includes: Determine at least one first detection point according to the first detected device; Controlling the first signal generating device to apply an electrical signal to the detection circuit according to the first detection point; The first signal measuring device measures the electrical signal of the detection circuit to obtain the first detection result; The first detected device is detected according to the compensated first detection result and the first detection point.

7. The instrument detection method according to claim 6, characterized in that: The first standard device is the first signal generating device, the instrument detection system is further used to detect a fourth detected device, the fourth detected device is a signal generating device, and the instrument detection method further includes: The detecting of the first detected device includes determining that the first detected device has a first allowable error; Determine at least one second detection point based on the fourth device under test, where the second detection point is within the measurement range of the fourth device under test and the first device under test, and the allowable error of the fourth device under test is greater than the first allowable error; The first standard device applies an electrical signal to the detection circuit according to the second detection point, the first detected device measures the electrical signal of the detection circuit, obtains a second detection result, and sends the second detection result to the main control system; The fourth detected device applies an electrical signal to the detection circuit according to the second detection point, the first detected device measures the electrical signal of the detection circuit, obtains a third detection result, and sends the third detection result to the main control system; The fourth detected device is detected based on the second detection point, the second detection result, and the third detection result.

8. The instrument detection method according to claim 6, characterized in that: The first standard device is the first signal measuring device, the instrument detection system is further used to detect a fifth device to be detected, the fifth device to be detected is a signal measuring device, and the instrument detection method further includes: The detecting of the first detected device includes determining that the first detected device has a first allowable error; Determine at least one third detection point based on the fifth detected device, wherein the third detection point is within the measurement range of the fifth detected device and the first detected device, and the allowable error of the fifth detected device is greater than the first allowable error; The first detected device applies an electrical signal to the detection circuit according to the third detection point, the first standard device measures the electrical signal of the detection circuit, obtains a fourth detection result, and sends the fourth detection result to the main control system; The first device under test applies an electrical signal to the detection circuit according to the third detection point, the fifth device under test measures the electrical signal of the detection circuit, obtains a fifth detection result, and sends the fifth detection result to the main control system; The fifth detected device is detected based on the three detection points, the fourth detection result and the fifth detection result.

9. A computer-readable storage medium, characterized in that: Computer instructions are stored thereon, and when the instructions are executed by a processor, the steps of the instrument detection method described in any one of claims 1 to 8 are implemented.

10. A main control system, characterized in that: Applied to the instrument detection system, the main control system is configured as follows: Sending a first generation control signal to a first signal generating device and sending a first connection control signal to a detection circuit, so that the first signal generating device is electrically connected to the detection circuit and applies a first electrical signal to the detection circuit, wherein the first signal generating device is one of a first standard device or a first detected device; At least partially simultaneously with the first generation control signal and the first connection control signal, a first measurement control signal is sent to a first signal measuring device, and a second connection control signal is sent to the detection circuit, so that the first signal measuring device is electrically connected to the detection circuit, and the first electrical signal transmitted by the detection circuit is measured to generate a first measurement result, wherein the first signal measuring device is the other of the first standard device or the first device under test; Sending a second generation control signal to the first signal generating device and sending a third connection control signal to the detection circuit, so that the first signal generating device is electrically connected to the detection circuit and applies a second electrical signal to the detection circuit, the second electrical signal being equal in value to the first electrical signal and opposite in direction, wherein the first signal generating device is controlled to switch the connection direction in the detection circuit, or the first signal measuring device is controlled to switch the connection direction in the detection circuit; At least partially simultaneously with the second generation control signal and the third connection control signal, sending a second measurement control signal to the first signal measurement device and sending a fourth connection control signal to the detection circuit, so that the first signal measurement device is electrically connected to the detection circuit and measures the second electrical signal transmitted by the detection circuit to generate a second measurement result; Acquire the first measurement result and the second measurement result from the first signal measuring device; calculating a contact potential difference of the detection circuit according to the first measurement result and the second measurement result; The contact potential difference is stored, a first detection result is obtained, and the first detection result is compensated according to the contact potential difference, wherein the first detection result is measurement information generated by detecting the first detected device based on the detection circuit.

11. An instrument detection system, characterized in that: The detection circuit includes a first standard device, the first standard device is a first signal generating device or a first signal measuring device, the instrument detection system is used to detect a first detected device, the first detected device is the first signal generating device or the first signal measuring device; In at least one measurement process, the detection circuit is electrically connected to the first signal generating device and the first signal measuring device, so that the first signal generating device applies a first electrical signal to the detection circuit, and the first signal measuring device measures the first electrical signal to generate a first measurement result; In at least one other measurement process, the detection circuit is electrically connected to the first signal generating device and the first signal measuring device, so that the first signal generating device applies a second electrical signal to the detection circuit, the first signal measuring device measures the second electrical signal, and generates a second measurement result, and the first measurement result and the second measurement result are used to calculate the contact potential difference of the detection circuit, wherein the first signal generating device is controlled to switch the connection direction in the detection circuit, or the first signal measuring device is controlled to switch the connection direction in the detection circuit, the second electrical signal is equal to the first electrical signal in value and opposite in direction; In at least one detection process, the detection circuit is electrically connected to the first standard device and the first detected device, and is used to detect the first detected device and generate a first detection result, and the contact potential difference is used to compensate for the first detection result.

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