Measuring Equipment

Abstract

To provide a measurement device with which it is possible to suppress ringing that is generated immediately after AC signal voltage is applied, and thereby suppress a delay in measurement initiation.SOLUTION: Provided is a measurement device comprising: a sinusoidal signal generation unit (13) for generating a sinusoidal signal; a voltage generation unit (16) for generating an AC signal voltage that corresponds to the sinusoidal signal; measurement terminals (Hp, Hc, Lp, Lc) for applying the AC signal voltage generated by the voltage generation unit (16) to a measurement object (100) and detecting the voltage and current outputted from the measurement object in response to the application of the AC signal voltage; and measurement units (31, 32, 35) for measuring the voltages and currents detected via the measurement terminals. A prescribed frequency component of the sinusoidal signal is suppressed for a first rise section of a voltage value that changes in shape of a sinusoidal wave, so that the sinusoidal signal is replaced with a correction signal having been corrected so as to more moderately change than a change in shape of the sinusoidal wave.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a measuring device, and more particularly to a measuring device capable of measuring electrical characteristics of an object to be measured by applying an AC signal voltage and measuring the current and voltage. [Background technology]

[0002] Patent Document 1 describes a measurement device that measures impedance as an electrical property of an object to be measured. This measurement device generates an AC signal voltage, which is a sine wave signal, applies it to the object to be measured, detects the voltage across the object to be measured and the current flowing through the object to be measured when the AC signal voltage is applied, and measures the impedance as an electrical property of the object to be measured. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-278977 A Summary of the Invention [Problem to be solved by the invention]

[0004] When applying an AC signal voltage to the device under test, immediately after the application of a sine wave signal to the device under test, a signal is suddenly applied from no input, and as a result, frequency components other than the desired signal frequency that should be applied to the device under test, i.e., unexpected frequency components, are applied to the device under test.

[0005] When an unexpected frequency component immediately after a signal is applied overlaps with the resonant frequency band determined by the generating circuit and the device under test, an unstable state occurs and ringing occurs in the voltage and current waveforms.

[0006] In order to obtain accurate measurement results with a measuring device, it is necessary to wait until the ringing converges before starting measurement. This poses a significant problem for measuring devices in which even a slight increase in takt time has a significant impact on productivity.

[0007] The present invention has been made in consideration of the above-mentioned problems in the conventional art, and an object of the present invention is to provide a measurement device that can suppress delays in starting measurement by suppressing ringing that occurs immediately after application of an AC signal voltage. [Means for solving the problem]

[0008] A measurement device according to a representative embodiment of the present invention includes a sine wave signal generating unit that generates a sine wave signal, a voltage generating unit that generates an AC signal voltage corresponding to the sine wave signal, measurement terminals that apply the AC signal voltage generated by the voltage generating unit to an object to be measured and detect the voltage and current output from the object to be measured in response to the application of the AC signal voltage, and a measurement unit that measures the voltage and current detected via the measurement terminals, and during the initial rising section of the voltage value that changes in a sinusoidal waveform, the sine wave signal is replaced by a correction signal that has been corrected to change more slowly than the change in the sine wave shape by suppressing a predetermined frequency component. Effect of the Invention

[0009] According to the measuring device of the present invention, it is possible to suppress a delay in starting measurement by suppressing ringing that occurs immediately after application of an AC signal voltage. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a measurement device according to an embodiment of the present invention. [Diagram 2] FIG. 13 is a diagram showing the waveform of an AC signal voltage in a conventional measuring device. [Diagram 3] 4 is a diagram showing a waveform of an AC signal voltage in the measurement device 1 of the present embodiment. FIG. [Figure 4] 3 is a diagram showing frequency characteristics of the AC signal voltage shown in FIG. 2. [Diagram 5] FIG. 4 is a diagram showing frequency characteristics of the AC signal voltage shown in FIG. [Figure 6]FIG. 6 is a diagram showing the frequency characteristics of FIG. 4 and FIG. 5 superimposed. [Figure 7] 10A and 10B are diagrams for explaining an example of a method for generating a correction signal. [Figure 8] FIG. 2 is a diagram illustrating an example of the configuration of a data storage unit 14. [Figure 9] 4 is a flow chart showing a process flow of capacitance measurement in the measurement device 1 of the present embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 1. Overview of the embodiment First, a typical embodiment of the invention disclosed in this application will be outlined. In the following description, as an example, reference numerals in parentheses are used to denote the components of the invention in FIG. 1.

[0012] [1] A measurement device according to a representative embodiment includes a sine wave signal generating unit (13) that generates a sine wave signal, a voltage generating unit (16) that generates an AC signal voltage corresponding to the sine wave signal, measurement terminals (Hp, Hc, Lp, Lc) that apply the AC signal voltage generated by the voltage generating unit (16) to a device under test (100) and detect a voltage and a current output from the device under test in response to the application of the AC signal voltage, and measurement units (31, 32, 35) that measure the voltage and current detected via the measurement terminals (Hp, Hc, Lp, Lc), and during the initial rising section of a voltage value that changes in a sinusoidal waveform, the sine wave signal is replaced by a correction signal that has been corrected so as to change more gradually than the change in the sine wave waveform by suppressing a predetermined frequency component.

[0013] According to this aspect, it is possible to suppress the delay in starting measurement by suppressing ringing that occurs immediately after application of the AC signal voltage.

[0014] [2] In the measurement device described in [1] above, the first rising edge section may be a section from the rising edge of the sine wave signal until a quarter of one period has elapsed.

[0015] According to this embodiment, when a quarter of one period of the sine wave signal has elapsed, the change in amplitude of the sine wave signal is the smallest. Therefore, by connecting the correction signal to the sine wave signal before being replaced at this timing, the change in the signal at the connection point can be further reduced, which contributes to stable measurement without signal disturbance.

[0016] [3] In the measurement device described in [1] or [2] above, the predetermined frequency component may be a frequency component in the vicinity of a resonant frequency of a circuit including the voltage generating unit and the device under test.

[0017] According to this aspect, the occurrence of unexpected frequency components near the resonant frequency of the circuit is suppressed, and as a result, ringing that occurs immediately after application of an AC signal voltage can be suppressed.

[0018] [4] In the measurement device described in [3] above, the correction signal may be a signal obtained by multiplying the first quarter wave of the sine wave signal by a window function that suppresses frequency components near the resonant frequency.

[0019] According to this aspect, a correction signal can be generated that is a signal corrected by suppressing a predetermined frequency component at the rising edge of the signal.

[0020] [5] In the measuring device described in any one of [1] to [4] above, the measuring device may further include an input unit that accepts input of measurement conditions, and a measurement condition setting unit that sets the measurement conditions based on the input measurement conditions, and the sine wave signal generating unit may generate a sine wave signal according to the measurement conditions set by the measurement condition setting unit.

[0021] According to this aspect, by generating a sine wave signal according to the measurement conditions, the start of measurement can be accelerated and delays in the start of measurement can be suppressed, thereby avoiding increases in tact time.

[0022] [6] In the measurement device described in [5] above, the measurement condition setting unit may determine, based on the input measurement conditions, that replacement with a correction signal is not possible if the time period for ringing to converge is shorter than the time period of the first quarter cycle of the sine wave signal, and determine that replacement with a correction signal is possible if the time period is longer than the time period of the first quarter cycle of the sine wave signal, and set the result of the determination as the measurement condition.

[0023] According to this aspect, instead of using a sine wave signal that takes into account the convergence time of the ringing, it is possible to advance the start of measurement according to the convergence time of the ringing, and thereby suppress delays in the start of measurement, thereby avoiding increases in takt time.

[0024] [7] In the measuring device described in [5] or [6] above, the measuring device may further include a data table in which correction data and sine wave data corresponding to the measurement conditions are pre-stored, and the sine wave signal generating unit may acquire the correction data and sine wave data pre-stored in the data table in accordance with the measurement conditions so as to replace the correction data and sine wave data with a correction signal corresponding to the measurement conditions.

[0025] According to this aspect, since a data table storing data corresponding to conditions is provided, measurements can be started sequentially based on the measurement conditions input by the operator, thereby increasing the processing speed.

[0026] [8] In the measurement device according to any one of [1] to [7] above, the measurement section may identify a capacitance of the device under test based on the measured voltage and current.

[0027] According to this aspect, it is possible to measure the capacitance of the device under test.

[0028] [9] In the measurement device described in any one of [1] to [7] above, the measurement section may determine the impedance of the device under test based on the measured voltage and current.

[0029] According to this aspect, it is possible to measure the impedance of the device under test.

[0030] 2. Specific examples of embodiments Hereinafter, specific examples of the embodiments of the present invention will be described with reference to the drawings. In the following description, components common to each embodiment will be given the same reference numerals, and repeated description will be omitted. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from the actual situation. The drawings may also include parts with different dimensional relationships and ratios.

[0031] (Embodiment) FIG. 1 is a diagram showing a schematic configuration of a measurement device according to this embodiment.

[0032] The measurement apparatus 1 of this embodiment can be configured as a measurement apparatus that performs capacitance measurement to specify the capacitance of a device under test (hereinafter also referred to as DUT: Device Under Test) 100 by measuring the voltage and current in the device under test 100 when an AC signal voltage is applied to the device under test 100. The device under test 100 can be, for example, a capacitor.

[0033] In the measurement device 1 of this embodiment, a voltage corresponding to a sine wave signal is generated as an AC signal voltage during measurement. Here, the sine wave signal and AC signal voltage generated in the measurement device 1 of this embodiment will be explained in comparison with those in a conventional measurement device.

[0034] Fig. 2 is a diagram showing the waveform of an AC signal voltage in a conventional measuring device. Fig. 3 is a diagram showing the waveform of an AC signal voltage in the measuring device 1 of this embodiment. Fig. 4 is a diagram showing the frequency characteristic of the AC signal voltage shown in Fig. 2. Fig. 5 is a diagram showing the frequency characteristic of the AC signal voltage shown in Fig. 3. Fig. 6 is a diagram in which the frequency characteristics of Fig. 4 and Fig. 5 are superimposed and displayed.

[0035] The AC signal voltage in the conventional measuring device has a sine wave shape as shown in FIG. 2. On the other hand, as shown in FIG. 3, the waveform of the AC signal voltage in this embodiment is basically sine wave like the conventional one, but during the first rising section, the waveform shape is different from the sine wave shape. As is clear from FIG. 3, during the first rising section, the waveform shape is corrected so that it changes more gently than the change in the sine wave shape. This is because the first rising section of the sine wave signal used to generate the AC signal voltage is replaced with a correction signal. The correction signal is a signal corrected by suppressing a predetermined frequency component at the signal rising edge.

[0036] The first rising section of the sine wave signal replaced by the correction signal is, for example, a section until one-quarter of one period of the sine wave signal to be replaced has elapsed. When one-quarter of one period of the sine wave signal has elapsed, the change in the amplitude of the sine wave signal is the smallest, so by connecting the correction signal to the sine wave signal before replacement at this timing, the change in the signal at the connection part can be reduced. Reducing the change in the signal at the connection part contributes to stable measurement without disturbing the signal. The point at which the correction signal is connected to the sine wave signal before replacement is not limited to the point where one-quarter of one period of the sine wave signal has elapsed, but may be any point where the change in the amplitude of the sine wave signal is small.

[0037] Here, a method for generating the correction signal will be described.

[0038] 7 is a diagram for explaining an example of a method for generating a correction signal. In this example, a generation method using a window function will be explained as an example, but the function used is not particularly limited.

[0039] As shown in Figure 7, a window function that gradually increases from 0 to 1 over the same time period as a quarter wave of a sine wave signal is used, which is then stretched to a specified period that is longer than the quarter wave of the original sine wave signal. The stretched window function is multiplied by the corresponding sine wave signal after removing the first time period, resulting in a time period equal to the quarter wave of the sine wave signal. By applying this type of processed window function to the first quarter wave of the sine wave signal, a correction signal can be generated, which is a signal that has been corrected by suppressing a specified frequency component at the rising edge of the signal.

[0040] The optimal window function is selected based on the measurement conditions and the resonant frequency components of the circuit. For example, by increasing the predetermined period for which the window function is extended, the frequency components to be suppressed will become higher frequency components. Therefore, the predetermined period for which the window function is extended can be adjusted according to the resonant frequency of the circuit.

[0041] In this way, the correction signal can be generated by applying a function that suppresses a specific frequency component at the rising edge of the signal to a quarter wave of the original waveform, which is the first rising section of the sine wave signal.

[0042] The frequency characteristic of the AC signal voltage shown in Fig. 2 has continuous frequency components with a peak at the frequency of the sine wave signal, as shown in Fig. 4. The frequency components of the sine wave signal are the frequency components of the AC signal voltage to be applied to the device under test. Frequency components other than the frequency components of the AC signal voltage to be applied to the device under test are considered to be unexpected frequency components, due to system disturbances caused by applying an AC signal voltage from a non-applied state in the circuit under test, including the measurement device.

[0043] On the other hand, the frequency characteristic of the AC signal voltage shown in Fig. 3 is the frequency characteristic shown in Fig. 5. As is clear from Fig. 6, it has in common with the frequency characteristic in Fig. 4 in that it has a peak at the frequency of the sine wave signal, but differs from the frequency characteristic in Fig. 5 in that a certain frequency component is suppressed. Specifically, the frequency characteristic shown in Fig. 5 has a portion where the components suddenly drop off around 5500 Hz.

[0044] In the measurement device 1 of this embodiment, the suppressed predetermined frequency component is near the resonant frequency of the circuit to be measured, including the measurement device. When the occurrence of unexpected frequency components near the resonant frequency of the circuit is suppressed, the ringing that occurs immediately after the application of the AC signal voltage can be suppressed. This is because the ringing is considered to occur when the unexpected frequency components that occur immediately after the application of the AC signal voltage cause the circuit to resonate. Therefore, the AC signal voltage generated according to the sine wave signal in which the sine wave signal in the first rising section is replaced by the correction signal in which the frequency components near the resonant frequency of the circuit to be measured are suppressed can suppress the ringing that occurs immediately after the application of the AC signal voltage.

[0045] In addition, since the correction signal is a different signal from the AC signal voltage for measurement, the voltage generated according to the correction signal cannot be used for measurement, so measurement is not started during the first quarter period.

[0046] In this way, in the measurement device 1 of this embodiment, a sine wave signal replaced with a correction signal is generated during the initial rising section, and an AC signal voltage signal corresponding to the replaced sine wave signal is generated, thereby suppressing ringing that occurs immediately after application of the AC signal voltage.

[0047] As shown in FIG. 1, the measuring device 1 of this embodiment is configured to include an input / output interface 10, an input section 11, a measurement condition setting section 12, a sine wave signal generating section 13, a data storage section 14, a D / A conversion circuit 15, a voltage generating circuit 16, a voltage measuring circuit 31, a current measuring circuit 32, an A / D conversion circuit 33, an A / D conversion circuit 34, a calculation section 35, and an output section 36.

[0048] The input / output interface 10 is an interface device used by the user to input information such as measurement conditions and to check measurement results. The input / output interface 10 is composed of, for example, a display screen that displays input information, measurement results, the status of the measurement device 1, and an operation unit such as a dial and buttons.

[0049] In the measuring device 1 of FIG. 1, the input section 11, the measurement condition setting section 12, the sine wave signal generating section 13, the data storage section 14, the calculation section 35, and the output section 36 can be configured by a microprocessor (MPU) 20 having hardware elements such as a processor such as a CPU, various memories such as ROM and RAM, a timer (counter), an A / D conversion circuit, an input / output I / F circuit, and a clock generating circuit, with each component being connected to each other via a bus or a dedicated line.

[0050] MPU 20 has, as functional units for generating a sine wave signal and measuring the capacitance of device under test 100, an input unit 11, a measurement condition setting unit 12, a sine wave signal generating unit 13, a data storage unit 14, a calculation unit 35, and an output unit 36. Each of these functional units can be realized, for example, by a processor of MPU 20 performing various calculations according to programs stored in a memory or the like, and controlling peripheral circuits such as an A / D conversion circuit and an input / output I / F circuit.

[0051] The input unit 11 accepts information such as measurement conditions input via the input / output interface 10 .

[0052] The measurement condition setting unit 12 sets the measurement conditions based on the information of the measurement conditions input via the input unit 11. For example, when the range of capacitance values ​​of a capacitor or the like to be measured and a measurement frequency, which is the frequency of an AC signal voltage signal to be input to the device under test, are input via the input unit 11, the measurement condition setting unit 12 determines whether or not to perform replacement with a correction signal based on this information. The measurement condition setting unit 12 sets the input measurement conditions, which are the range of capacitance values ​​and the measurement frequency, and the information on whether or not replacement with the determined correction signal is possible, as the measurement conditions.

[0053] Here, the setting of the measurement conditions will be described. In the measurement device 1 of this embodiment, the correction signal is a signal different from the sine wave signal corresponding to the AC signal voltage for measurement, so the voltage generated according to the correction signal is not used for the capacitance measurement of the device under test 100. That is, when a sine wave signal replaced with a correction signal is used, the capacitance measurement of the device under test 100 is not started during the first quarter period. On the other hand, when a sine wave signal not replaced with a correction signal is used, ringing occurs, so that the capacitance measurement of the device under test 100 cannot be started until the ringing converges. Therefore, in the measurement device 1 of this embodiment, the measurement condition setting unit 12 determines that the replacement by the correction signal is impossible when the time period during which the ringing converges is shorter than the time period of the first quarter period of the sine wave signal, and determines that the replacement by the correction signal is possible when the time period is longer than the first quarter period of the sine wave signal. With this configuration, the delay in starting the measurement can be suppressed, so that an increase in the tact time can be avoided.

[0054] The measurement condition setting unit 12 outputs the set measurement conditions to the sine wave signal generating unit 13 and the calculation unit 35 .

[0055] The sine wave signal generating unit 13 generates a sine wave signal based on the measurement conditions. The sine wave signal generating unit 13 obtains sine wave data and correction data according to the measurement conditions from the data storage unit 14, and outputs them to the D / A conversion circuit 15.

[0056] The data storage unit 14 pre-stores sine wave data and correction data for each measurement condition.

[0057] Fig. 8 is a diagram showing an example of the configuration of the data storage unit 14. As shown in Fig. 8, the data storage unit 14 stores the correction data (value of the correction signal) for each measurement frequency replaced by the correction signal, and the sine wave data (value of the sine wave signal) for each measurement frequency not replaced by the correction signal. That is, the data storage unit 14 is a data table that stores the correction data and the sine wave data for each measurement condition (measurement frequency and whether or not replacement by the correction signal is possible).

[0058] The sine wave signal generating unit 13 acquires sine wave data or correction data corresponding to the measurement frequency and whether or not replacement with a correction signal is possible from the data storage unit 14, and generates a sine wave signal.

[0059] The D / A conversion circuit 15 converts the input digital sine wave signal into an analog sine wave signal and outputs it to the voltage generation circuit 16 .

[0060] Voltage generating circuit 16 generates a voltage according to the input analog sine wave signal as an AC signal voltage, and inputs a measurement current to device under test 100 via terminal Hc. Voltage measuring circuit 31 can be configured, for example, by a gain amplifier, but is not limited to this configuration.

[0061] Voltage measurement circuit 31 measures the voltage across device under test 100 via Hp terminal and Lp terminal. Voltage measurement circuit 31 can be configured, for example, by a differential amplifier circuit, a filter circuit, and a gain amplifier, but is not limited to these configurations.

[0062] Current measuring circuit 32 measures the current input from terminal Lc, i.e., the current that has flowed through device under test 100. Current measuring circuit 32 can be configured with an IV conversion circuit, a filter circuit, and a gain amplifier, but is not limited to these configurations.

[0063] The A / D conversion circuit 33 converts the voltage measured by the voltage measurement circuit 31 into a digital signal and outputs it to the calculation unit 35.

[0064] The A / D conversion circuit 34 converts the current measured by the current measurement circuit 32 into a digital signal and outputs it to the calculation unit 35 .

[0065] The calculation unit 35 performs capacitance measurement to measure the capacitance value of the device under test 100 based on the voltage measured by the voltage measurement circuit 31 and the current measured by the current measurement circuit 32. The calculation unit 35 performs capacitance measurement based on the measurement conditions set by the measurement condition setting unit 12. If the set measurement conditions specify that a correction signal is to be used, the calculation unit 35 waits until a quarter period of the sine wave signal has elapsed from the start of measurement before starting the capacitance measurement. If the set measurement conditions specify that a correction signal is not to be used, the calculation unit 35 waits until ringing has converged before starting the capacitance measurement.

[0066] The output section 36 outputs the capacitance determined by the capacitance measurement to the input / output interface 10 .

[0067] Next, the process flow of capacitance measurement in the measurement device 1 of this embodiment will be described.

[0068] FIG. 9 is a flow diagram showing the process flow of capacitance measurement in the measurement device 1 of this embodiment.

[0069] First, when the measurement conditions are received at the input unit 11 via the input / output interface 10 (step S1), the measurement condition setting unit 12 judges whether or not the measurement conditions satisfy the convergence condition (step S2). For example, it is judged that the convergence condition is satisfied when the time period during which ringing in the AC signal voltage generated based on the measurement conditions in a circuit corresponding to the measurement conditions converges is shorter than the time period of the first quarter period of the sine wave signal.

[0070] If it is determined in step S2 that the convergence condition is not satisfied (step S2: NO), the sine wave signal generating unit 13 retrieves sine wave data replaced by a correction signal at the measurement frequency of the measurement conditions from the data storage unit 14, and generates a sine wave signal replaced by the correction signal (step S3).

[0071] On the other hand, if it is determined in step S2 that the convergence condition is satisfied (step S2: YES), the sine wave signal generating unit 13 acquires normal sine wave data that is the measurement frequency of the measurement conditions and has not been replaced by a correction signal from the data storage unit 14, and generates a sine wave signal that has not been replaced by a correction signal (step S5).

[0072] The sine wave signal generating unit 13 determines whether a time period of a quarter cycle of the sine wave signal has elapsed since the start of generation of the sine wave signal (step S4), and if it determines that the time period has elapsed (step S4: YES), it obtains from the data storage unit 14 normal sine wave data that is the measurement frequency of the measurement conditions and has not been replaced by a correction signal, and generates a sine wave signal that has not been replaced by a correction signal (step S5).

[0073] When the sine wave signal generating unit 13 determines that a time period of a quarter cycle of the sine wave signal has not elapsed since the start of generation of the sine wave signal (step S4: NO), it retrieves the sine wave data replaced by the correction signal from the data storage unit 14 and generates a sine wave signal replaced by the correction signal (step S3).

[0074] The sine wave signal generating unit 13 repeats the process of step S5 until it determines that the generation of the sine wave signal has ended (step S6).

[0075] In this way, the measurement device 1 of this embodiment generates a sine wave signal replaced with a correction signal during the first rising section, and generates an AC signal voltage signal according to the replaced sine wave signal, thereby suppressing ringing that occurs immediately after application of the AC signal voltage. Furthermore, when the convergence condition is not satisfied, an increase in the tact time can be avoided by using the sine wave signal replaced with the correction signal.

[0076] (Modification of the embodiment) Although the measurement device of the above embodiment has been described with specific examples, it is not limited thereto, and various modified forms can be adopted. For example, the configuration of the measurement device 1 is not limited to the configuration shown in Fig. 1. For example, the input side configuration (input unit 11, measurement condition setting unit 12, sine wave signal generating unit 13, data storage unit 14) and the output side configuration (calculation unit 35, output unit 36) may be configured as separate MPUs 20.

[0077] For example, the data storage unit 14 may be configured to store, for each measurement frequency, a sine wave signal in which only the first wave has been replaced by a correction signal and a normal sine wave signal.

[0078] Furthermore, for example, the flow diagram showing the process flow of capacitance measurement is not limited to the configuration in Fig. 9. Instead of acquiring correction data (step S3) and determining whether or not a time period of a quarter cycle of the sine wave signal has elapsed (step S4) when the convergence condition is not satisfied (step S2: NO), a configuration may be adopted in which a sine wave signal in which only the first wave has been replaced by a correction signal is acquired from the data storage unit 14.

[0079] In the above embodiment, the measurement device 1 has been described as a so-called capacitance meter that measures the capacitance of the device under test 100, but is not limited to this. The measurement device 1 may be, for example, an LCR meter that measures the impedance of the device under test 100 or a reactance meter that measures the reactance. [Explanation of symbols]

[0080] 1 measuring device, 10 input / output interface, 11 input section, 12 measurement condition setting section, 13 sine wave signal generating section, 14 data storage section, 15 D / A conversion circuit, 16 voltage generating circuit, 20 MPU, 31 voltage measurement circuit, 32 current measurement circuit, 33 A / D conversion circuit, 34 A / D conversion circuit, 35 calculation section, 36 output section, 100 device under test (DUT)

Claims

1. a sine wave signal generating unit that generates a sine wave signal; a voltage generating unit that generates an AC signal voltage according to the sine wave signal; a measurement terminal for applying the AC signal voltage generated by the voltage generating unit to an object to be measured and detecting a voltage and a current output from the object to be measured in response to the application of the AC signal voltage; A measurement unit that measures the voltage and current detected through the measurement terminals, During an initial rising section of a voltage value that changes in a sinusoidal waveform, the sinusoidal signal is replaced with a correction signal that is corrected to change more slowly than the sinusoidal waveform by suppressing a predetermined frequency component. Measuring equipment.

2. 2. The measuring device according to claim 1, The first rising edge section is a section from the rising edge of the sine wave signal until a quarter of one period has elapsed. Measuring equipment.

3. 3. The measuring device according to claim 1 or 2, the predetermined frequency component is a frequency component in the vicinity of a resonant frequency of a circuit including the voltage generating unit and the device under test; Measuring equipment.

4. The measuring device according to claim 3, The correction signal is a signal obtained by multiplying the first quarter wave of the sine wave signal by a window function that suppresses frequency components near the resonance frequency. Measuring equipment.

5. The measuring device according to any one of claims 1 to 4, an input unit for receiving input of measurement conditions; A measurement condition setting unit that sets measurement conditions based on the input measurement conditions, The sine wave signal generating unit generates a sine wave signal according to the measurement conditions set by the measurement condition setting unit. Measuring equipment.

6. The measuring device according to claim 5, the measurement condition setting unit determines that replacement with a correction signal is not possible if the time period during which ringing converges is shorter than the time period of the first quarter cycle of the sine wave signal based on the input measurement conditions, and determines that replacement with a correction signal is possible if the time period is longer than the time period of the first quarter cycle of the sine wave signal, and sets the determination result as the measurement condition. Measuring equipment.

7. 7. The measuring device according to claim 5 or 6, Further comprising a data table in which correction data and sine wave data corresponding to the measurement conditions are stored in advance, The sine wave signal generating unit obtains compensation data and sine wave data pre-stored in the data table in accordance with measurement conditions so as to replace the sine wave data with a compensation signal corresponding to the measurement conditions.

8. The measuring device according to any one of claims 1 to 7, The measurement unit identifies a capacitance of the device under test based on the measured voltage and current. Measuring equipment.

9. The measuring device according to any one of claims 1 to 7, The measurement unit identifies the impedance of the device under test based on the measured voltage and current. Measuring equipment.

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