JPH10123189A - Measurement method and device for resistance value - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the true resistance of a resistor to be measured accurately by eliminating the influence caused by the thermoelectromotive force due to the connection of different types of metals such as a measurement terminal and a measurement conductor and due to the temperature difference between those connection points. SOLUTION: Measurement value I and -I of the same value are fed from a DC current supply means F to a resistor RX to be measured in one and the other directions, thus measuring two voltage drops EX and -EX' generated at the resistor RX to be measured by a differential amplifier A after setting them to the same polarity. Then, measurement values EA and EA' of the two voltage drops EX and -EX' of the resistor RX to be measured are averaged by an operation means B and at the same time a value obtained by dividing using a current- equivalent value EI that is equivalent to the measurement current I is displayed as the resistance of the resistor RX to be measured by a display means C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance measuring method for measuring a DC resistance of a resistor having a low resistance by, for example, a four-terminal method.

[0002]

2. Description of the Related Art As a first conventional resistance value measuring method for measuring DC resistance, a measuring current is applied to a measured resistor to measure a voltage drop generated in the measured resistor, and a voltage of the measured resistor is measured. There has been a method in which a value obtained by dividing a measured value of a drop by a current equivalent value corresponding to a measured current is output as a resistance value of a resistor to be measured. Further, as a second conventional resistance value measuring method,
There is a method in which a specified measurement current is applied to a known resistor to be measured, a voltage drop occurring in the resistor to be measured is measured, and a measured value of the voltage drop of the resistor to be measured is output as a resistance value of the resistor to be measured. .

FIG. 5 shows a block diagram of a resistance value measuring apparatus for realizing the first resistance value measuring method described above. The resistance measuring apparatus, as shown in FIG. 5, the first and second measurement current supply to be connected to both ends of the measuring resistor R _X
Measurements terminals 1 and 2 connected to the pair of output ends of the DC current generating means D, third and fourth measuring terminal 3 for voltage measurement to be connected to both ends of the measuring resistor R _X,
4 is connected to a non-inverting input terminal and an inverting input terminal of a differential amplifier A as a measuring means. Further, it inputs the measured value E _A output is a voltage of the differential amplifier A to the arithmetic means BY, have entered the current equivalent value E _I is output as voltage from the DC current generating means D to the computing means BY. Further, the calculation result of the calculation means BY is supplied to the display means C. Incidentally, E _T is equivalently shows the thermal electromotive force generated due to the temperature difference between connection and their dissimilar metals in measuring terminal 1-4 or measuring conductor connector portion (not shown).

FIG. 7 shows how a conventional resistance measuring device measures a resistance. In FIG. 7, reference numeral 10 denotes a main body of the resistance value measuring device, 11 and 12 are measurement terminals for supplying current, 13 and 14 are measurement terminals for voltage measurement, respectively.
Reference numerals 15 to 18 denote measurement conductors each having one end connected to the measurement terminals 11 to 14, and reference numerals 19 to 22 denote measurement conductors 15 to 14, respectively.
Reference numeral 18 denotes a clip for holding and connecting a lead wire connected to the other end of the resistor 18, reference numeral 23 denotes a resistor under test, and reference numerals 23a and 23b denote lead wires of the resistor under test 23.

[0007] In the resistance value measuring apparatus shown in FIG. 7, a measuring conductor 15 is connected to measuring terminals 11 to 14 of a main body 10 of the resistance value measuring apparatus.
To 18 are connected to each other, and a measurement current is applied to the measured resistor 23 in a state where the lead wires 23a and 23b of the measured resistor 23 are sandwiched by clips 19 to 22 as shown in FIG. The voltage between 23b will be measured.

In the case of the measurement system shown in FIG. 7 as an example, there are many connection points of different metals. As a connection portion of the dissimilar metal, for example, a connector portion 3 for connecting one end of the measurement conductors 15 to 18 to the measurement terminals 11 to 14 is used.
1. The other end of the measuring conductors 15 to 18 and the soldered connection portion 32 of the clips 19 to 22, the clips 19 to 22 and the lead wire 2.
There is a connection portion 33 between 3a and 23b and a welded portion 34 between the lead wires 23a and 23b to the resistor body 23c of the resistor 23 to be measured.

[0007] A temperature difference of 1 ° C. or less or several degrees C. or less can be considered between the connecting portions of a plurality of different metals as described above. The temperature difference may be caused by unevenness in the room temperature of the measurement room, the influence of wind from a cooler, an air conditioner, a fan, or the like, or the measurement terminal 1 caused by the heat generated by the main body 10 of the resistance measurement device.
A rise in the temperature of the portions 1 to 14 and self-heating (Joule heat) due to the measured current of the resistor 23 to be measured are considered, and a thermoelectromotive force is generated by this temperature difference.

In the case of measuring the resistance of a chip resistor having no lead wire, a contact pin, a probe, or the like is used instead of the clip, and the probe is connected (contacted) to the electrode portion. Also, a thermoelectromotive force is generated in the same manner as described above. The resistance value measuring operation of the resistance value measuring device having the above-described configuration will be described below. First
The second, third and fourth measurement terminal 1-4 is connected to the measurement resistor R _X, the measured resistance from the DC current generating means D in this state through the first and second measurement terminals 1 vessel R _X flushed with measured current I from the first measurement terminal 1 to the second direction of the measuring terminal 2, third and fourth measurement terminal to be measured resistor occurs between 3, 4 R _X voltage drop E _X is input to the differential amplifier A. As a result, measured values E _A corresponding to the voltage drop E _X of the measured resistor R _X is generated from the differential amplifier A. With corresponding current equivalent value E _I (.alpha. I) of the measured values E _A measurement current I is input to the arithmetic unit BY,
In operation means BY performs the operation of E _A / E _I, arithmetic means BY operation result is displayed on the display unit C as the resistance value of the measurement resistor R _X.

At this time, the third and fourth measuring terminals 3 and 4
Resistor R measured through _XVoltage drop E_XTo
Is the thermoelectromotive force E_TAnd the measured resistor R to be measured
_XVoltage drop E_XIs E_X= I × R_X+ E_T And the above E_A/ E_ICalculation
Measured resistor R_XWhen calculating the resistance value of
Force E_TWill include an error. This error
Is the measured resistor R_XIf the resistance of
Resistance R_XVoltage drop (I × R_X)
Is the thermoelectromotive force E_TBecause it is much larger than
It is as small as possible.

[0010] As shown in FIG. 6, as a resistance value measuring device for realizing the second resistance value measuring method, a DC current flowing a specified measurement current I _R (constant current) in place of the DC current generating means D is used. using generator DR, using the arithmetic means BRY that eliminates the need for dividing the measured value E _a by the differential amplifier a at a current equivalent value E _I instead of the operation means B, the measurement resistor on the display unit C The value corresponding to the resistance value of R _X is displayed, and the others are the same as those in FIG.
Thus can be eliminated the dividing at a current equivalent value E _I is the measured current value flowing through the measured resistor R _X are known unchanged, set inside the computing means BRY its value as a coefficient This is because it is possible to keep it.

[0011]

However, in the above-described resistance measuring device, when measuring the resistance value of the low-resistance resistor R _X , particularly when measuring the resistance R _X , for suppressing the measured current low self-heating generated by I, or measured current I is limited to the allowable power or less measured current value of the measurement resistor R _X, greater the resistance to be measured becomes small, the voltage drop of the measured resistor R _X becomes small, the third and fourth measurement terminals 3 and 4
Alternatively, the effect of the thermoelectromotive force generated in the measurement conductor connector cannot be ignored.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to eliminate the influence of thermoelectromotive force due to the connection of dissimilar metals such as a measurement terminal and a measurement conductor connector and the temperature difference between those connection points, thereby realizing the true resistance value of the resistor to be measured. Is to provide a resistance value measuring method and a resistance value measuring device capable of accurately measuring the resistance value.

[0013]

According to the present invention, a positive-polarity measuring current and a negative-polarity measuring current having the same value are respectively supplied to a resistance to be measured, and a voltage drop of the resistance to be measured when each measurement current flows is measured. Then, by calculating the average value of the measured values of the two voltage drops, or by dividing the average value by a value corresponding to the measured current, the error due to the thermoelectromotive force, which is an error factor, is canceled, and the true value of the measured resistor is measured. The resistance value is measured accurately.

[0014]

According to a first aspect of the present invention, there is provided a method for measuring a resistance value, wherein a measurement current having the same value is applied to a resistor to be measured in one direction and another direction, and two voltage drops generated in the resistor to be measured are respectively measured. Measure with the same polarity.
A value obtained by averaging the measured values of the two voltage drops and dividing by the current equivalent value corresponding to the measured current is output as the resistance value of the resistor to be measured.

According to this method, the same current is applied to the measured resistor in one direction and the other direction, and two voltage drops generated in the measured resistor are measured with the same polarity. Since the measured value of the drop is averaged and divided by the current equivalent value corresponding to the measured current, the resistance value of the measured resistor can be measured in a state where the error due to the thermoelectromotive force which is an error factor is canceled out, As a result, the true resistance value of the measured resistor can be accurately measured.

According to a second aspect of the present invention, there is provided a method for measuring a resistance value, wherein a specified measurement current having the same value is applied to the measured resistor in one direction and the other direction, and two voltage drops generated in the measured resistor are made to have the same polarity. Then, a value obtained by averaging two measured values of the voltage drop of the measured resistor is output as the resistance value of the measured resistor. According to this method, a specified measurement current having the same value is applied to the measured resistor in one direction and the other direction, and two voltage drops generated in the measured resistor are measured with the same polarity. Since the measured values are averaged, the resistance value of the measured resistor can be measured in a state where the error caused by the thermoelectromotive force, which is an error factor, is cancelled. As a result, the true resistance value of the measured resistor can be accurately determined. Can be measured. Moreover, since there is no need to divide by the current equivalent value corresponding to the measured current, the resistance value of the measured resistor can be obtained by a simple calculation.

According to a third aspect of the present invention, there is provided a method of measuring a resistance value, in which a measurement current having the same value is applied to a measured resistor in one direction and another direction, and two voltage drops generated in the measured resistor are measured. The measured values of the two voltage drops of the measuring resistor are averaged with the same polarity, and a value obtained by dividing by the current equivalent value corresponding to the measuring current is output as the resistance value of the measured resistor.

According to this method, a measurement current having the same value is applied to the resistor to be measured in one direction and the other direction, and two voltage drops generated in the resistor to be measured are measured.
The measured values of the two voltage drops are averaged with the same polarity, and divided by the current equivalent value corresponding to the measured current. Measurement can be performed, and as a result, the true resistance value of the measured resistor can be accurately measured.

According to a fourth aspect of the present invention, there is provided a method for measuring a resistance value, wherein a prescribed measurement current having the same value is applied to the measured resistor in one direction and the other direction, and two voltage drops generated in the measured resistor are measured. The measured values of the two voltage drops of the measured resistor are averaged with the same polarity and output as the resistance value of the measured resistor. According to this method, the same measured voltage is applied to the measured resistor in one direction and the other direction to measure the two voltage drops generated in the measured resistor, and the measured values of the two voltage drops are equalized. Since the polarity is averaged, the resistance value of the measured resistor can be measured in a state where the error due to the thermoelectromotive force, which is an error factor, is canceled out. As a result, the true resistance value of the measured resistor can be accurately measured. Can be measured. Moreover, since there is no need to divide by the current equivalent value corresponding to the measured current, the resistance value of the measured resistor can be obtained by a simple calculation.

According to a fifth aspect of the present invention, there is provided a resistance value measuring device, wherein first and second measuring terminals for supplying a measuring current are respectively connected to both ends of a measured resistor, and voltages respectively connected to both ends of the measured resistor. Third and fourth measurement terminals for measurement; DC current supply means for flowing a measurement current of the same value from the first and second measurement terminals to the resistor to be measured so as to be switchable in one direction and the other direction; Measuring means for measuring a voltage drop of the measured resistor generated between the third and fourth measuring terminals;
A switch provided between the third and fourth measuring terminals and the measuring means and having the same polarity irrespective of the direction of the measuring current and applying a voltage drop of the measured resistor to the measuring means; Average the value measured by the measuring means when the measuring current is flowing in the direction and the value measured by the measuring means when the measuring current is flowing in the resistor to be measured in the other direction, and divide by the value equivalent to the measured current And a display means for displaying the calculation result of the calculation means as a resistance value of the resistor to be measured.

According to this configuration, the same current is applied to the resistor to be measured in one direction and the other direction, and two voltage drops occurring in the resistor to be measured are measured with the same polarity. Since the measured value of the drop is averaged and divided by the current equivalent value corresponding to the measured current, the resistance value of the measured resistor can be measured in a state where the error due to the thermoelectromotive force which is an error factor is canceled out, As a result, the true resistance value of the measured resistor can be accurately measured.

According to a sixth aspect of the present invention, there is provided a resistance value measuring device, wherein first and second measuring terminals for supplying a measuring current are respectively connected to both ends of a resistor to be measured, and voltages respectively connected to both ends of the resistor to be measured. Third and fourth measurement terminals for measurement, DC current supply means for flowing a specified measurement current of the same value from the first and second measurement terminals to the resistor to be measured so as to be switchable in one direction and the other direction, A measuring means for measuring a voltage drop of the measured resistor generated between the third and fourth measuring terminals; and a measuring means provided between the third and fourth measuring terminals and the measuring means, irrespective of the direction of the measuring current. Switch means for applying the voltage drop of the measured resistor to the measuring means by setting the polarity, and the measured value by the measuring means when the measuring current is flowing in one direction to the measured resistor and measuring in the other direction to the measured resistor When current is flowing Comprises a calculating means for averaging the measured values by a constant means, and display means for displaying the calculation result of the calculating means as the resistance value of the measured resistor.

According to this configuration, the same measured current is applied in one direction and the other direction to the measured resistor, and two voltage drops generated in the measured resistor are measured to have the same polarity. Since the measured value of the voltage drop is averaged, the resistance value of the measured resistor can be measured in a state where the error caused by the thermoelectromotive force, which is an error factor, is cancelled. As a result, the true resistance value of the measured resistor is measured. Can be accurately measured. Moreover, since there is no need to divide by the current equivalent value corresponding to the measured current, the resistance value of the measured resistor can be obtained by a simple calculation.

According to a seventh aspect of the present invention, there is provided a resistance value measuring device, wherein first and second measuring terminals for supplying a measuring current are respectively connected to both ends of a resistor to be measured, and voltages which are respectively connected to both ends of the resistor to be measured. Third and fourth measurement terminals for measurement; DC current supply means for flowing a measurement current of the same value from the first and second measurement terminals to the resistor to be measured so as to be switchable in one direction and the other direction; Measuring means for measuring a voltage drop of the measured resistor generated between the third and fourth measuring terminals;
Average the values measured by the measuring means when the measured current flows in one direction to the measured resistor and the measured values by the measuring means when the measured current flows in the other direction to the measured resistor, and average them. Calculation means for dividing by a value corresponding to the measured current, and display means for displaying the calculation result of the calculation means as the resistance value of the resistor to be measured.

According to this configuration, the same current is applied to the measured resistor in one direction and the other direction, and two voltage drops are measured in the measured resistor.
The measured values of the two voltage drops are averaged with the same polarity, and divided by the current equivalent value corresponding to the measured current. Measurement can be performed, and as a result, the true resistance value of the measured resistor can be accurately measured.

According to the eighth aspect of the present invention, there is provided a resistance value measuring apparatus, wherein first and second measuring terminals for supplying a measuring current are respectively connected to both ends of a resistor to be measured, and voltages respectively connected to both ends of the resistor to be measured. Third and fourth measurement terminals for measurement, DC current supply means for flowing a specified measurement current of the same value from the first and second measurement terminals to the resistor to be measured so as to be switchable in one direction and the other direction, Measuring means for measuring a voltage drop of the measured resistor generated between the third and fourth measuring terminals, and a measured value and a measured resistance obtained by the measuring means when a measuring current flows in one direction in the measured resistor. Calculating means for averaging the values measured by the measuring means when the measuring current is flowing in the other direction in the same direction with the same polarity, and displaying means for displaying the calculation result of the calculating means as the resistance value of the resistor to be measured. It has.

According to this configuration, the same measured voltage is applied in one direction and the other direction to the measured resistor to measure two voltage drops generated in the measured resistor, and the two voltage drops are measured. Since the values are averaged with the same polarity, the resistance value of the measured resistor can be measured in a state where the error caused by the thermoelectromotive force, which is an error factor, is canceled out. As a result, the true resistance value of the measured resistor is measured. Can be accurately measured. Moreover, since there is no need to divide by the current equivalent value corresponding to the measured current, the resistance value of the measured resistor can be obtained by a simple calculation.

Hereinafter, a resistance value measuring method according to an embodiment of the present invention will be described with reference to the drawings. The first embodiment method of measuring the resistance of the invention, as shown in FIG. 1, the measured current I, respectively the same value in one direction and the other direction to the measurement resistor R _X from the direct current supply means F, by flowing -I 2 two voltage drop E _X caused the measured resistor R _X, -E _X '
The changeover switch element S _3, S is the measurement unit in the same polarity with ₄ differential amplifiers (e.g., AD620 of Analog Devices, Inc.) were measured at A, 2 of the measured resistor R _X by the computing means B One of the voltage drop E _X display, 'measure E _a of, E _a' -E _X as the resistance value of the current corresponding value E to be measured resistor divided by the value in the _I R _X corresponding to the measured current I with averaging This is a method of displaying and outputting by means C.

According to this method of measuring the resistance value, the measurement currents I and -I having the same value flow in the resistor R _X in one direction and the other direction, respectively, and the two voltage drops E generated in the resistor R _X are measured. _X and −E _X ′ are measured with the same polarity, respectively.
Two voltage drop E _X, -E _X 'measurements of E _A, E _A' averaged and measured current current equivalent value corresponding to I E _I (alpha
Since division by I), can measure the resistance value of the measurement resistor R _X in a state of canceling an error due to thermal electromotive force E _T which cause errors, so that the true measured resistor R _X Can be accurately measured.

Measurement of resistance value according to the second embodiment of the present invention
The method is, as shown in FIG.
Measured resistor R_XSame in one direction and the other
The specified measurement current I of the value_R, -I_RAnd the measured resistor R
_XVoltage drop E occurring at _X, -E_X′ Switch
H element S_Three, S_FourWith the same polarity to increase the differential
Each is measured by the width meter A, and the resistance to be measured is calculated by the arithmetic means BR.
Bowl R_XTwo voltage drops E_X, -E_X'Measured value E_A,
E_AThe condition that the measured current is constant
Under test R_XDisplay means C as the resistance value of
This is a method of displaying more.

[0031] According to the resistance value measuring method, defined measurement current I _R of the respective identical values in one direction and the other direction to the measurement resistor R _X, -I _R flushed with the two occurring to the measured resistor R _X voltage drop E _X, -E _X 'was measured in the same polarity, respectively, two voltage drop E _X, -E _X' measurements of E _a,
Since averaging E _A ', it is possible to measure the resistance value of the measurement resistor R _X in a state of canceling an error due to thermal electromotive force E _T which cause errors, so that, in the measurement resistor R _X The true resistance value can be accurately measured. Moreover,
It is not necessary to divide a current corresponding value corresponding to the measured current, it can be determined resistance value of the measurement resistor R _X with a simple operation.

The third resistance measuring method of the embodiment of this invention, as shown in FIG. 3, the measurement of each of the same value in one direction and the other direction to the measurement resistor R _X from the direct current supply means F current I, -I flushed with two voltage generated in the measurement resistor R _X drop E _X, respectively measured by the differential amplifier a is the measurement means -E _X ', the measured resistor by the computing means BX two voltage drop E _X of R _X, the measured value of -E _X 'E _a,
Measurement current I to be measured resistor divided by the current corresponding value E _I equivalent to R with the -E _A 'averaged in the same polarity
_This is a method of displaying and outputting the resistance value of _{X by} the display means C.

According to this resistance value measuring method, the resistance to be measured
Bowl R_XMeasurement voltage in one direction and the other in the other direction.
Flow the current I, -I_XTwo electricity generated in
Pressure drop E_X, -E_X'And measure two voltage drops
Lower E_X, -E_X'Measured value E _A, -E_A′ With the same polarity
And a current equivalent value E corresponding to the measured current I
_I(∝I), so that the thermoelectromotive force E, which is an error factor,
_TWith the error caused by the_XNo
The resistance value can be measured, so that the resistor R
_XCan be accurately measured.

Measurement of resistance value according to the fourth embodiment of the present invention
The method is as shown in FIG.
Measured resistor R_XSame in one direction and the other
The specified measurement current I of the value_R, -I_RAnd the measured resistor R
_XVoltage drop E occurring at _X, -E_X′ By measuring means
Each is measured by a certain differential amplifier A and sent to the arithmetic means BRX.
Measured resistor R_XTwo voltage drops E_X, -E_X'of
Measured value E_A, -E_AAre averaged with the same polarity
Constant resistor R_XThe measured current is constant as the resistance value of
To display and output with the display means C under the following conditions:
Is the law.

According to this resistance value measuring method, the resistance to be measured is
Bowl R_XMeasurement of the same value in one direction and the other
Constant current I_R, -I_RAnd the measured resistor R_XOccur in
Two voltage drops E_X, -E_X′ And measure two
Voltage drop E_X, -E_X'Measured value E_A, -E_A′
Since the polarity is averaged, the thermoelectromotive force E, which is an error factor, _T
With the error caused by the_XResistance
The value of the resistor R_X
Can be accurately measured. Only
Need not be divided by the current equivalent value corresponding to the measured current.
Therefore, the resistor to be measured R_XThe resistance value of
Can be

Hereinafter, the resistance value measurement according to the embodiment of the present invention will be described.
The apparatus will be described with reference to the drawings. The first of the present invention
FIG. 1 shows a block diagram of a resistance value measuring device according to an embodiment.
You. As shown in FIG. 1, this resistance value measuring device
Resistor R_XFor supplying the measuring current connected to both ends of the
DC current supply means for connecting the first and second measurement terminals 1 and 2
F respectively connected to a pair of output terminals, and a resistor to be measured R_X
Third and third for voltage measurement respectively connected to both ends of
4 measurement terminals 3 and 4 are connected to the switching element S_Three, S _FourThrough
And the non-inverting input terminal of the differential amplifier A as the measuring means and
Each is connected to the inverting input terminal.

The DC current supply means F above, the measurement current I can the same value switching from the first and second measurement terminals 1 in one direction and the other direction to the measurement resistor R _X, -I
And has a function of flowing DC current, and comprises a DC current generating means D and two changeover switching elements S ₁ and S ₂ for switching the current polarity. The differential amplifier A has third and fourth measurement terminals 3, 4
Voltage drop E _X of the measured resistor R _X occurring during, -E _X '
Has the function of measuring The changeover switch elements S ₃ and S ₄ provided between the third and fourth measuring terminals 3 and 4 and the differential amplifier A are connected to a resistor to be measured generated between the third and fourth measuring terminals 3 and 4. R _X of the voltage drop E _X, the -E _X ',
Measurement current I, in the same polarity regardless of the direction of -I, it has a function of applying That voltage drop E _X, the differential amplifier A in the same polarity as the E _X '.

From the differential amplifier A, the resistor to be measured R
_XVoltage drop E when the measurement current I flows in one direction
_XThe measured value E which is the output voltage corresponding to_AOccurs and the measured
Constant resistor R_XWhen the measurement current -I flows in the other direction
Voltage drop E_X'Is the measured value that is the output voltage corresponding to
E_A'Occurs. Then, from the differential amplifier A to the arithmetic means
To B, the voltage drop E_XMeasurement by differential amplifier A corresponding to
Fixed value E_AAnd voltage drop E_X', The differential amplifier A corresponding to
Measured value E _A′ Is input, and the DC current generating means
Current equivalent value E output as a voltage from D_IIs entered
You. The calculating means B calculates the value measured by the differential amplifier A.
E_A, E _A'Averaged to the current equivalent to the measured current I
Value E_IIt has a function of dividing by (∝I). This calculation means
B is, for example, a measurement value E of an analog signal (not shown).
_AA / D converter for converting A / D into a digital signal,
Holds the output data of the D converter, and
Microcontroller that performs operations such as averaging and division as described above.
It is composed of a computer and the like.

[0039] Furthermore, the operation result of the arithmetic unit B is supplied to the display unit C, is displayed in the operation result, for example, a digital value as a resistance value of the measurement resistor R _X on the display unit C. Incidentally, E _T is equivalently shows the thermal electromotive force generated due to the temperature difference between connection and their dissimilar metals in measuring terminal 1-4 or measuring conductor connector. Here, FIG.
The procedure for measuring the resistance value by the resistance value measuring device will be described. First, the changeover switch elements S ₁ , S ₂ , S ₃ , S ₄
The switch to a side, respectively, to the measurement resistor R _X from the DC current generating means D, the changeover switch element S _1, S ₂
, A measurement current I flows from the first measurement terminal 1 to the second measurement terminal 2. Voltage drop E _X in this state the third and the measurement resistor appears between the fourth measurement terminals 3, 4 R _X
Is measured. This voltage drop E _X of the measured resistor R _X, include thermoelectromotive force E _T, represented by _{E X = I × R X +} E T.

[0040] When inputting a voltage drop E _X of the measuring resistor R _X to the differential amplifier A via the selector switch element S _3, S _4, the measured values corresponding to the voltage drop E _X from the differential amplifier A E _A (∝E _X ) occurs, which is added to the arithmetic means B and held. Next, the changeover switch elements S ₁ , S
_2, S _3, S ₄ switched to side b, respectively, to the measurement resistor R _X from the DC current generating means D, measured from the changeover switch element S _1, S ₂ through the second measurement terminal 2 first A measurement current -I flows in the direction of the terminal 1. In this state the third
And the measured resistor R appearing between the fourth measuring terminals 3 and 4
_X for measuring the voltage drop -E _X 'of. This measured resistor R
_X voltage drop -E _X ', the include thermoelectromotive force E _T, -E _X' represented by _{= -I × R X + E T} .

The voltage drop across the measuring resistor R _X -E _X '
The invert the polarity changeover switch element S _3, S ₄ via the differential amplifier A 'by entering as a differential amplifier the voltage drop E _X from A' voltage drop E _X measured values corresponding to E _A '
(.Alpha.E _X ') is generated, it is held applied to the operation means B. The voltage drop E _X 'is, E _X' will be expressed as = I × R _X -E _T.

The arithmetic means B calculates (E _A + E _A ') based on the measured values E _A , E _A ' by the differential amplifier A and the current equivalent value E _I (∝I) given from the DC current generation means D. ) / (2 · E _I ) is performed, and the calculation result is calculated as the thermoelectromotive force E _T
Is output as the true resistance value of the measured resistor R _X from which the effect of (1) has been removed, and this is displayed as the resistance value on the display means C.

[0043] Here, a description will be made on the influence of the thermal electromotive force E _T is removed by the operation of the resistance value calculated. Resistance of the measurement resistor R _X is represented by _{R X = (E X + E} X ') / (2 · I). By transforming this _{expression, R X = {(I ×} R X + E T) + (I × R X -E T)} /
(2 × I) = (I × R X) / it next, it is understood that the term of thermoelectromotive force E _T is off.
_{Here, E X, E X ',} I respectively E _A, E _A', E
Since it is proportional to _I , as described above, when the calculation of (E _A + E _A ′) / (2 · E _I ) is performed, the resistance of the measured resistor R _X from which the influence of the thermoelectromotive force E _T is removed is obtained. A true resistance value is required.

According to the resistance measuring apparatus of this embodiment, the measurement currents I and -I having the same value flow in the resistor R _X in one direction and the other direction, respectively, and the resistance R _X is generated in the resistor R _X. one of the voltage drop E _X, -E _X 'were measured respectively in the same polarity, two voltage drop E _X, -E _X' measurements of E _a, the E _a 'average, and corresponds to the measured current I Since the division by the current equivalent value E _I , the thermal electromotive force E
The resistance value of the measured resistor RX can be measured with the error due to _T canceled, and as a result, the measured resistor R _X
The true resistance value of _X can be accurately measured.

FIG. 2 is a block diagram showing a resistance measuring apparatus according to a second embodiment of the present invention. As shown in FIG. 2, this resistance value measuring device uses a DC current generating means DR for generating a known prescribed measurement current I _R instead of the DC current generating means D of FIG. Calculation means B
Instead of giving the current equivalent value E _I to R each time it is measured,
Calculation means BR using a value corresponding to current equivalent value E _I as a coefficient
Sure you set, under the condition that the current is constant, without dividing the current value corresponding E _I, only performs the calculation of _{(E A + E A ')} / 2, the measured resistance those which make it possible to determine the resistance of the vessel R _X, other configurations 1
Is the same as that of the resistance value measuring device. Note that the calculation means BR in this embodiment is basically the same as the operation means B, and the program in that it does not perform the division by current equivalent value E _I differ.

According to the resistance measuring apparatus of this embodiment, the specified measurement currents I _R and −I _R having the same value flow in the resistor R _X in one direction and the other direction, respectively, and the resistance R _X is measured. two voltage drop E _X occurring, -E _X 'each was measured in the same polarity, two voltage drop E _X, -E _X'
Since the average of the measured values E _A, the E _A ', it is possible to measure the resistance value of the measurement resistor R _X in a state of canceling an error due to thermal electromotive force E _T which cause errors, as a result, the the true resistance of the measuring resistor R _X can be accurately measured. Moreover, since the measurement current I _R is no need to divide by the corresponding current value corresponding to, it can be obtained resistance value of the measurement resistor R _X with a simple operation.

FIG. 3 is a block diagram showing a resistance measuring apparatus according to a third embodiment of the present invention. As shown in FIG. 3, this resistance value measuring device includes the changeover switch elements S ₃ ,
Eliminating the S _4, but the polarity reversal function by switching the switch elements S _3, S ₄ is realized by computing means BX, other configuration is the same as in FIG. That is, as shown in FIG. 3, the resistance value measuring apparatus includes first and second measuring terminals 1 and 2 for supplying a measuring current connected to both ends of a resistor to be measured R _X , respectively. respectively connected to a pair of output ends of the non-inverting input of the differential amplifier a is the third and fourth measuring means measuring terminals 3 and 4 for voltage measurement to be connected to both ends of the measuring resistor R _X Terminal and the inverting input terminal.

The DC current supply means F above, the measurement current I can the same value switching from the first and second measurement terminals 1 in one direction and the other direction to the measurement resistor R _X, -I
And has a function of flowing DC current, and comprises a DC current generating means D and two changeover switching elements S ₁ and S ₂ for switching the current polarity. The differential amplifier A has third and fourth measurement terminals 3, 4
Voltage drop E _X of the measured resistor R _X occurring during, -E _X '
Has the function of measuring

From the differential amplifier A, the resistor to be measured R
Voltage drop E when measurement current I flows in one direction in _X
X in measured values E _A is the output voltage is generated corresponding in output voltage corresponding to the voltage drop -E _X 'when are the measured current -I in the other direction flow to be measured resistor R _X Some measurements-
E _A 'occurs. Then, the arithmetic unit BX from the differential amplifier A, a differential amplifier A which corresponds to the measured values E _A and the voltage drop -E _X 'by the differential amplifier A which corresponds to the voltage drop E _X
Measurements -E _A 'and is inputted by, further direct current generator current equivalent value E _I is output as voltage from the D is input. The arithmetic means BX has a function of dividing the measured value E _A by the differential amplifier A, a current equivalent value -E _A 'corresponds to the measured current on average in the same polarity E _I (αI). The arithmetic means BX, although not shown, holds e.g. measured value of the analog signal E _A, and A / D converter for converting the -E _A 'into a digital signal, the output data of the A / D converter, The average as described above for the retained data,
It is composed of a microcomputer or the like that performs operations such as division.

[0050] Furthermore, the operation result of the arithmetic unit BX is supplied to the display unit C, is displayed in the operation result, for example, a digital value as a resistance value of the measurement resistor R _X on the display unit C.
Note that E _T is equivalent to the thermoelectromotive force as described above. Here, a procedure for measuring a resistance value by the resistance value measuring device of FIG. 3 will be described. First, the changeover switch elements S ₁ ,
Switch to a side S _2, respectively, to the measurement resistor R _X from the DC current generating means D, the changeover switch element S _1,
A measurement current I flows from the first measurement terminal 1 to the second measurement terminal ₂ through S2. In this state to measure the voltage drop E _X of the third and fourth measurement terminal to be measured resistor appears between 3, 4 R _X. Voltage drop E _X of the measurement resistor R _X
The, it includes thermoelectromotive force E _T, represented by _{E X = I × R X +} E T.

The resistor to be measured R_XVoltage drop E_XThe difference
When input to the dynamic amplifier A, the voltage drop from the differential amplifier A
E_XMeasured value E corresponding to_A(∝E_X) Occurs and it is
It is added to the arithmetic means BX and held. Next, switch
Switch element S₁, S_TwoAre switched to the b side respectively,
From the current generating means D to the measured resistor R_XFor the switch
Switch element S₁, S_TwoThrough the second measuring terminal 2
The measurement current -I flows in the direction of the first measurement terminal 1. This state
The measured resistance appearing between the third and fourth measuring terminals 3 and 4
Armor R_XVoltage drop -E _X'. This measured resistance
Armor R_XVoltage drop -E_X'Contains the thermoelectromotive force E_TContains
-E_X'= -I × R_X+ E_T It is represented by

[0052] Voltage drop the measuring resistor R _X -E _X '
Is input to the differential amplifier A, the differential amplifier A outputs a measured value −E _A ′ (∝−E ′) corresponding to the voltage drop −E _X ′.
_X ') occurs, which is applied to the arithmetic means BX and held. The arithmetic unit BX, based measurements E _A by the differential amplifier A, -E _A 'and the DC current generating means provided from the D current equivalent value E _I and (.alpha. I) to, {E _A - (- E _A ') Perform the calculation represented by _I / (2 · E _I ), and calculate the calculation result as the thermoelectromotive force E _T
Is output as the true resistance value of the measured resistor R _X from which the effect of (1) has been removed, and this is displayed as the resistance value on the display means C.

[0053] Here, a description will be made on the influence of the thermal electromotive force E _T is removed by the operation of the resistance value calculated. Resistance of the measurement resistor R _X is, R _X = represented by _{{E X - - (E X} ')} / (2 · I). By transforming this _{expression, R X = [(I ×} R X + E T) - {- (I × R X -
E _T )｝] / (2 × I) = (I × R _X ) / I, which indicates that the term of the thermoelectromotive force E _T has disappeared.
_{Here, E X, -E X ',} I respectively E _A, -
Since it is proportional to E _A ′ and E _I , as described above, when the operation of {E _A − (− E _A ′} / (2 · E _I ) is performed, the influence of the thermoelectromotive force E _T is removed. true resistance of the measuring resistor R _X that is being asked.

According to the resistance measuring apparatus of this embodiment, the measurement currents I and -I having the same value flow in the resistor R _X in one direction and the other direction, respectively, and are generated in the resistor R _X. one of the voltage drop E _X, -E _X 'were measured respectively, two voltage drop E _X, -E _X' measurements of E _a, -E
_{Since A} ′ is averaged with the same polarity and divided by the current equivalent value E _I corresponding to the measured current I, the resistor R _X is measured in a state where the error due to the thermoelectromotive force E _T which is an error factor is canceled.
You can measure the resistance value, as a result, it is possible to accurately measure the true resistivity of the measured resistor R _X.

FIG. 4 is a block diagram showing a resistance measuring apparatus according to a fourth embodiment of the present invention. The resistance measuring apparatus, as shown in FIG. 4, in place of the direct current generator D of FIG. 3, using a direct current generating means DR for generating a known prescribed measurement current I _R, the direct current generator DR Calculation means B
Instead of giving the current equivalent value E _I to the RX every time measurement is performed, the value corresponding to the current equivalent value E _I is set as a coefficient in the arithmetic means BRX, and under the condition that the current is constant. , without dividing the current value corresponding _{E I, {E a - (} - E a ')} / 2 of only performing the operation, which make it possible to determine the resistance value of the measurement resistor R _X Fig. 1
Is the same as that of the resistance value measuring device. Note that the calculation means BXR in this embodiment is basically the same as the operation means BX, the program in that it does not perform the division by current equivalent value E _I differ.

According to the resistance measuring apparatus of this embodiment, the specified measurement currents I _R and −I _R having the same value flow in the resistor R _X in one direction and the other direction, respectively, and the resistance R _X is measured. two voltage drop E _X occurring, -E _X 'were measured respectively, two voltage drop E _X, -E _X' measurements E _a of the -E _a 'since the average in the same polarity, the error factor resistance of the measurement resistor R _X in a state of canceling an error due to thermal electromotive force E _T to be able to measure, as a result, that accurately measure the true resistivity of the measured resistor R _X Can be. Moreover, since the measurement current I _R is no need to divide by the corresponding current value corresponding to, it can be obtained resistance value of the measurement resistor R _X with a simple operation.

The present invention can be applied to resistance measurement by the two-terminal method. In this case, the first measuring terminal and the third measuring terminal
Are common, and the second and fourth measurement terminals are common.

[0058]

According to the resistance value measuring method and the resistance value measuring device of the present invention, two voltages generated in the measured resistor by flowing the same measured current in one direction and the other direction in the measured resistor, respectively. Since each drop is measured and the measured values of the two voltage drops are averaged, the error due to the thermo-electromotive force, which is an error factor, can be canceled out. As a result, the true resistance value of the measured resistor can be accurately measured. be able to. Especially,
If a specified measurement current is allowed to flow as the measurement current, the calculation means does not need to divide by the current equivalent value, and the calculation process is simple.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a resistance value measuring device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a resistance value measuring device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a resistance value measuring device according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a resistance value measuring device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of an example of a conventional resistance value measuring device.

FIG. 6 is a block diagram showing the configuration of another example of a conventional resistance value measuring device.

FIG. 7 is a perspective view showing how a resistance value is measured by a conventional resistance value measuring device.

[Explanation of symbols]

Reference Signs List 1 first measuring terminal 2 second measuring terminal 3 third measuring terminal 4 fourth measuring terminal A differential amplifier (measuring means) B computing means BR computing means BX computing means BRX computing means C display means D DC current Generation means DR DC current generation means F DC current supply means R _X Resistor to be measured

Claims (8)

[Claims] 1. A measurement current having the same value is applied to a resistor to be measured in one direction and another direction, and two voltage drops generated in the resistor to be measured are measured with the same polarity. A mean value of two measured values of the voltage drop occurring at the same time, and outputting a value obtained by dividing by a current equivalent value corresponding to the measured current as a resistance value of the resistor to be measured. 2. A method according to claim 1, further comprising the step of: flowing a specified measurement current having the same value in one direction and another direction in the resistor to be measured and measuring two voltage drops generated in the resistor with the same polarity. A method for measuring a resistance value, characterized in that a value obtained by averaging two measured values of the voltage drop of a tester is output as a resistance value of the measured resistor. 3. A measurement current having the same value is applied to the measured resistor in one direction and the other direction, and two voltage drops generated in the measured resistor are measured, and two voltage drops generated in the measured resistor are measured. A method for measuring a resistance value, comprising: averaging measured values of a voltage drop with the same polarity; and dividing the average by a current equivalent value corresponding to the measured current, and outputting the resultant value as a resistance value of the resistor to be measured. 4. A measured current having the same value is applied to the measured resistor in one direction and the other direction, respectively, and two voltage drops generated in the measured resistor are measured, respectively. A method for measuring a resistance value, characterized in that a measured value of a voltage drop is averaged with the same polarity and output as a resistance value of the resistor to be measured. 5. A first and a second measuring terminals for supplying a measuring current connected to both ends of a resistor to be measured, and a third and fourth terminals for measuring a voltage respectively connected to both ends of the resistor to be measured. And a DC current supply means for flowing a measurement current of the same value from the first and second measurement terminals to the resistor to be measured so as to be switchable in one direction and the other direction, and the third and fourth measurement terminals. A measuring means for measuring a voltage drop of the resistor to be measured which occurs between the measuring terminals; and a measuring means provided between the third and fourth measuring terminals and the measuring means to have the same polarity regardless of the direction of the measuring current. A switch means for applying a voltage drop of the measured resistor to the measuring means, and a value measured by the measuring means when a measured current flows in one direction in the measured resistor, and another value added to the measured resistor. The measured current in the direction Calculating means for averaging the value measured by the measuring means when flowing and dividing by a current equivalent value corresponding to the measured current; and displaying the calculation result of the calculating means as a resistance value of the measured resistor. A resistance value measuring device comprising a display means. 6. A first and a second measuring terminals for supplying a measuring current respectively connected to both ends of a resistor to be measured, and third and fourth terminals for measuring a voltage respectively connected to both ends of the resistor to be measured. And DC current supply means for flowing a prescribed measurement current of the same value from the first and second measurement terminals to the resistor to be measured so as to be switchable in one direction and the other direction, and the third and fourth measurement terminals. Measuring means for measuring a voltage drop of the resistor to be measured, which is generated between the measuring terminals, and the same polarity irrespective of the direction of the measuring current provided between the third and fourth measuring terminals and the measuring means. A switch means for applying a voltage drop of the measured resistor to the measuring means, and a measurement value and a measured value by the measuring means when a measurement current flows in one direction to the measured resistor. Measured in the other direction A resistance value measuring device comprising: a calculating means for averaging a value measured by the measuring means when a flow is flowing; and a display means for displaying a calculation result of the calculating means as a resistance value of the measured resistor. 7. A first and a second measuring terminals for supplying a measuring current respectively connected to both ends of a resistor to be measured, and third and fourth terminals for measuring a voltage respectively connected to both ends of the resistor to be measured. And a DC current supply means for flowing a measurement current of the same value from the first and second measurement terminals to the resistor to be measured so as to be switchable in one direction and the other direction, and the third and fourth measurement terminals. Measuring means for measuring a voltage drop of the measured resistor generated between measurement terminals, and a measurement value and a measured value by the measuring means when a measurement current flows in one direction to the measured resistor. Calculating means for averaging the values measured by the measuring means when the measuring current is flowing in the other direction and averaging the same and dividing by a current equivalent value corresponding to the measuring current; and Resistance of the measured resistor And a display unit for displaying the value as a value. 8. First and second measurement terminals for supplying a measurement current connected to both ends of a resistor to be measured, and third and fourth terminals for voltage measurement connected to both ends of the resistor to be measured, respectively. And DC current supply means for flowing a prescribed measurement current of the same value from the first and second measurement terminals to the resistor to be measured so as to be switchable in one direction and the other direction, and the third and fourth measurement terminals. Measuring means for measuring a voltage drop of the measured resistor generated between the measuring terminals of the measuring device, and a value measured by the measuring means when the measuring current flows in one direction in the measured resistor and the measured resistor Calculating means for averaging the values measured by the measuring means when the measuring current is flowing in the other direction and having the same polarity, and displaying means for displaying the calculation result of the calculating means as the resistance value of the resistor to be measured. And a resistor with Value measuring device.