Some standard content:
1 Scope
National Standard of the People's Republic of China
Direct-current potentiometers
Direct-current potentiometersUDC 621.317.7
1621.3.024
GB3927—83
rlEC523
1975(1979)
This standard applies to direct-current potentiometers with an accuracy level of 0.0001～0.1 [1ppm～1000pm (parts per million) 1×10-6～1×10-3 (scientific notation)], and to the internal auxiliary equipment of the above-mentioned potentiometers. This standard does not apply to potentiometers that automatically obtain zero balance, does not apply to potentiometers that obtain partial indication values by using the detector scale, and does not apply to external auxiliary equipment used with potentiometers. 2 Terms and Definitions
The following definitions apply to this standard.
2.1 DC potentiometer (hereinafter referred to as potentiometer) E).C potentiometer is an instrument for measuring voltage, which uses a known voltage to balance the voltage being measured. The known voltage can be obtained by a fixed current flowing through an adjustable resistor or by an adjustable current flowing through a specified resistor, or by a combination of them. 2.2 Measuring dials
The dial used to determine the value of the measured value. If any, it should also be multiplied by the corresponding range factor. 2.3 Effective range
For a specified range factor, the range of dial indications that the potentiometer can measure with a specified accuracy. 2.4 Range-changing device A device that can multiply the effective range by a coefficient called the "range factor" (such as 0.1). z.5 standardization of a potentiometer The adjustment necessary to ensure the correct indication of a potentiometer when measuring. 2.6 dial setting
After the potentiometer is standardized, when determining the voltage to be measured, the indication of the measuring dial after the potentiometer is balanced. If necessary, it is necessary to multiply by the range factor.
2.1 auxiliary equipment auxiliary equipment necessary to ensure that the potentiometer can operate accurately and safely as specified. It may or may not be part of the potentiometer body.
2.8 resolution
equivalent to a step voltage or the minimum division voltage of the lowest value measuring dial. 2.9 circuit insulation voltage (nominal circuit voltage), circuit insulation voltage (nominal circuit voltage) the highest voltage to ground that can be applied to the potentiometer circuit without becoming dangerous to the contact potentiometer. Note: Auxiliary circuits (if any) may have different values of line insulation voltage (nominal line voltage). 2.10 Ripple content (of a quantity) RMS value of the fluctuating component
RMS value of the ripple component
2.11 Leakage current screen (circuit)
National Bureau of Standards 1983-11-08 Issued
Leakage current screen (circuit) 1984-06-01 Implementation
GB3927-83
A conductive path to prevent leakage current from affecting the measurement result. 2.12 Electrostatic shielding Electrostatic shielding A conductive shell or coating that protects the enclosed space from external static electricity. 2.t3 Measuring terminals
Terminals connected to the voltage circuit to be measured.
2.14 Measuring circuit The circuit inside the potentiometer that is conductively connected to (or can be conductively connected to) the measuring end. 2.15 Measured quantity circuit selector switch The switch that can select each measuring end to be connected to the measuring line. 2.16 Residual electromotive force of a potentiometer The open circuit voltage that appears on the measuring end due to the insulation effect of the potentiometer itself when the potentiometer is operated and its measuring disks are all set to zero. 2.17 Incremental linearity The comprehensive linearity of the potentiometer is expressed in the following two aspects: a) The voltage generated by any two different measuring disk indications of the same value is constant; b) The voltage increment generated between two adjacent indications of any measuring disk is constant. 2.18 Influence quantity
In addition to the measured quantity, the quantity that is easy to cause the dial indication to change unexpectedly. 2.19 Common mode voltage The voltage that exists separately or jointly (as specified) between a certain measuring terminal (called the common mode voltage reference terminal) and the ground terminal, or the leakage current shield terminal, or the electrostatic shield terminal. 2.20 Variation with influence quantity The difference between two measured values of the same measured quantity when a certain influence quantity reaches two different specified values in turn. 2.21 Reference conditions The conditions under which the potentiometer meets the specified basic error. 2.22 Reference value rcference value
A specified single value of an influence quantity, within its specified tolerance, the potentiometer meets the requirements of the relevant basic error. 2.23 Reference range rcference range
The specified numerical range of the influence quantity, within which the potentiometer meets the requirements of the relevant basic error. 2.24 Nominal use range The specified range that each influence quantity value can take when the variation caused by nominal range does not exceed the specified limit. 2.25 limiting values of an influcnce quantity the maximum value that an influcnce quantity can take without damaging the potentiometer or causing permanent changes so that it no longer meets the accuracy grade requirements.
2.26 fiducial value
a single value used as a reference for the effective range in order to specify the accuracy of the potentiometer. Unless otherwise specified by the manufacturer, the fiducial value of the effective range is specified as the largest integer of 10 in the range. For example: the maximum dial indication of the potentiometer is 1.8√, and the range factors are 1, 0, 1 and .01. The fiducial values of the effective ranges are 1.0V, 0.1V and 0.01V respectively.
2.27 error
the value obtained by subtracting the true value of the measured value from the dial indication. Since the true value cannot be determined by measurement, the value obtained under the specified test conditions and within the specified time is used instead. This value is derived from the national measurement standard or the measurement standard agreed upon by the user and the manufacturer. Note: The error of any auxiliary equipment not attached to the potentiometer is not included in the potentiometer error. 2.28 Basic error intrinsicerror
The error determined under reference conditions.
2.29 Accuracy accuracy
GB3927-83
The accuracy of the potentiometer is limited by the basic error limit and the variation limit caused by the influencing quantity! 2.30 Accuracy class accuracyclass
The grade of the potentiometer. All potentiometers that meet all the requirements of this standard can use the same number to express their accuracy. 2.31 Grade index classindex
The number indicating the accuracy grade.
2.92 Distortion Factor (total harmonic wave of a quantity) Distortion Factor (total harmonic wave of a quantity) Root mean square value of wave component*
Rectangular value of non-sinusoidal quantity
3 Classification
Electrical equal difference specified in this standard, according to 2.The accuracy grades defined in Article 30 are classified as follows: a
1+× 10 -6
2×10-
5 × 10-
1 ×10-5
2 ×10-5
5oppin
5 ×10-
100ppn
1 ×10-4
200ppm
2 ×10-
The grade index of the potentiometer can be expressed as a percentage, b as ppm, and in scientific notation. If the potentiometer has multiple measuring ranges, each range can have its own grade index. 4 Limits of basic error
500ppm
5 ×10
lonoppm
1x10-3
If the conditions of use, transportation and maintenance specified in the manufacturing order are observed, the potentiometer shall meet the corresponding basic error limits specified for its respective accuracy level within one year from the date of delivery and verification or another date agreed upon by the manufacturer (or the supplier of the product) and the user.
For potentiometers, time-related stability is a basic feature. Here it is only specified as one year, but experience has shown that the rate of change caused by aging decreases with time.
4.1 Allowable limits of basic error
The allowable limit of the error of the potentiometer consists of two parts: a constant term related to the reference value;
a variable term proportional to the dial indication. The positive and negative limits are given by the binomial. Em=+-
Where: E... is the permissible limit of error, V; Un
is the reference value,
- is the scale indication, V
C-... is the grade index, expressed in percentage. *Except the fundamental wave.
GB 3927-83
When the grade index C is expressed in pm, the following formula should be used: Elim=±
1000000
When the grade index ℃ is expressed in scientific notation, the following formula should be used: Eim =
4.2 Incremental linearity
(2)
4.2.1 The difference in the error of any two dial indications corresponding to the same measured value shall not exceed half of the permissible limit of the basic error.
4.2.2 The difference between the indication errors of any two adjacent scales of any measuring disk shall not exceed half of the average value of the permissible limit of the basic error with the same indication sign. 4.3 Resolution
The resolution shall not exceed:
%U, (the grade index c is expressed in percentage). 0.5-
-U (the grade index c is expressed in Ppm).
1000000
0.5cU, (the grade index c is expressed in scientific notation). 4. With range converter
If the potentiometer needs to be re-standardized when the range is changed, the manufacturer shall indicate it. 4.5 Standardized independent circuit of potentiometer
If the potentiometer is standardized by independent circuit instead of measuring disk on any range, the additional error introduced by such standardization shall not exceed half of the permissible basic error. 5 Determination of basic error
5.1 The reference values of the relevant influencing quantities are shown in Table 1. 5.2 Before any measurement, there should be sufficient time for the potentiometer to reach a stable state and reach equilibrium at the reference value of the influencing quantity. 5.3 The leakage current shield and electrostatic shield (if any) should be connected according to the manufacturer's instructions. Table 1 Reference conditions and tolerances of influencing quantities Reference conditions (unless otherwise specified by the manufacturing unit) Indicated value 40% ~ 60% 0.0001 ~0.001 0.002~0.01 0.02 ~0.1 Grade index 20~100 200~1000 Scientific notation 1×10 -5~1×10-5
2×10-5~1×10-4
2×10-4~1×10-
Tolerance for test purposes?
±0,5 ℃
Influence on the relative wave length?
Common mode voltage
Auxiliary power supply voltage before excitation (if necessary)
Auxiliary power supply frequency (if necessary)
Auxiliary power supply distortion (if necessary)
External magnetic field
Reference conditions (unless otherwise specified by the manufacturer)
|Less than 0.1%
At least 5 minutes
Nominal value or
Nominal range
Nominal value or
Nominal range
Absent completely
GB3921-83
Continued Table 1
Grade index
No allowance is not allowed for reference range or nominal range. Forward:
All grades
All grades
All grades
All grades
②When indicating the temperature, the manufacturer shall select* from 20 ℃, 23 ℃ and 27 ℃. Scientific notation
Allowance for test purpose
±0.1% of reference value
+5% of nominal value
± 1 of nominal value %
The distortion coefficient shall not exceed 5%
The value of the earth's magnetic field strength
③This involves the ripple component of the relevant external DC power supply, the ripple of the external voltage reference source (if any) and the ripple selected on the DUT.
①The effect of DC power supply changes is not considered, they are generally excluded in the standardization process. 6 Allowable variation
6.1 Limit of variation
When the potentiometer is under the reference conditions given in Table 1 and the single influence disk is changed according to 6.2, the variation shall not exceed the specified values in Table 2 and 6.3.
Adopted statement:
IEC523-75 (first revision in 1979) "Current potentiometer" original text is "According to IEC160, it should be selected from 20℃, 23℃ and 27℃. Influence
Temperature
refers to
DC common mode voltage
Auxiliary power supply telephone
(if necessary)
Auxiliary power supply frequency
(if necessary)
Auxiliary power supply distortion
(if necessary)
External magnetic field
GB 3927—83
Table 2 Limits of nominal use range and allowable transformer level index
0.0001 ~0.001
0,002~0.01
0.02 ~ 0.1
20~100
200～1000
All grades
All grades
All grades
All grades
All grades
Scientific mark
1×10-h~ 1× 10 -5
2×10-51×10 -
2×10-1 ~1× 10 3
Nominal out-of-service range
limit (unless the manufacturer
has specified
24± 2
20± 5 ℃
2U ± 1n℃
25% and No. 75
reference range±10%
or the lower limit of the reference range-10% and the upper limit of the reference range+[0%
reference range: 5%
or the upper limit of the reference range+5% or the lower limit of the reference range-5%
the distortion coefficient does not exceed
zero and is specified by the manufacturing unit The value of
is: ① expressed as a fraction of the allowable basic error. ②; the resistance seen between the two terminals of the measured value, that is, the circuit resistance, should not exceed 10k. Allowable variation
6.2 Determination of variation conditions
6.2.1 The variation should be determined for each influencing variable. During each measurement, all other influencing quantities should be kept under their natural conditions. 6.2.2 The variation is evaluated as follows:
6.2.2.1 When a reference value is specified for a potentiometer, the influence quantity shall vary between this value and any value within the limits of the nominal range of use given in Table 2.
6.2.2.2 When a reference range and a nominal range of use are specified for a potentiometer, the influence quantity shall vary between the limits of the reference range and any value within the adjacent part of the nominal range of use. 6.3 Determination of the influence of common-mode voltage
The influence of common-mode voltage depends on the electrical properties of the external circuit being measured. The influence of common-mode voltage may be determined by the direct method given in Appendix A, or by the indirect method given in Appendix B. If the housing of the potentiometer is made of insulating material, a conductive support plate may be used instead of the ground terminal. GB392783
Determination of the influence of common-mode voltage Tests shall only be carried out in cooperation between the manufacturer and the user. 6.4 Variation due to external magnetic field
When the variation is measured within the nominal range of use determined by the manufacturer (see Table 2), it shall not exceed the limits specified in Table 2. The instrument for this quality test is described in Appendix C of this standard*, or by mutual agreement between the manufacturer and the user, other devices capable of producing a uniform magnetic field may be used in the case where the test device does not exist. The currents in the diagram shall be the direct current of each direction and the alternating current of the power supply frequency (45 to 65 Hz) in sequence. Note: The purpose of this test is to determine the sufficiency and effectiveness of the direct current of the instrument device (e.g. current comparator potentiometer) in the external magnetic field. However, it should be noted that when the voltage level formed by the device is operated in the alternating magnetic field, the alternating current in the circuit can produce the main culprit. This alternating current can produce the DC error in the following ways. Interaction between the voltage and the zeroing instrument:
b. A DC error voltage is generated on the rectifying potential layer in the circuit (such as copper oxide on the switch contacts or the chemical interface of the standard battery).
Therefore, when using the potentiometer, appropriate precautions should be taken to avoid errors. 7 Additional electrical and mechanical requirements
7.1 Voltage test and other safety requirements
The test voltage of the potentiometer is related to its line insulation voltage (nominal line voltage). The table lists the voltages corresponding to the line insulation medium voltage (nominal line voltage) of each line. Table 3 Line insulation voltage (nominal line voltage), marking and test voltage of measuring line Line insulation voltage (nominal line voltage) of measuring line V Adoption instructions, according to the requirements of examples C-1 to C-3 of Table 5 of the standard, the mathematical * left in the star symbol, no numbers Test voltage (RMS value) * The original text of IEC523 is: "As stated in Section 63.1 of IEC51 publication. \*[The original text of EC523 is: "The speed test and other safety requirements are included in IEC414 "Safety requirements for indicating and recording electric measuring instruments and their devices", which has become a reference."
*The key text of IEC414 is: "According to the requirements of Article 4.2, the numbers in the house diameter number are placed inside the house diameter number.\The insulation voltage of the measuring line
Voltage (nominal line voltage) V
GB3927-83
Continued Table 3
According to the requirements of C-1~C3 examples in Table 5 of this standard
, placed inside the star symbol 7.2 Functional insulation test bzxZ.net
7.2.1 The purpose of this test is to determine that when measuring a source resistance of up to 10k9 or a resistance to ground of 10k2 or more, the internal leakage of the potentiometer will not significantly reduce the measurement accuracy. 7.2.2 Under a voltage of 500V ± 10% DC, the insulation resistance value measured between any two points without any connection shall not be less than the value in Table 4. The value is given in the table.
The test should be carried out between 1 and 2 minutes after the voltage is applied. Table 4 Minimum value of insulation resistance
Grade index
0.,0001 ~0.001
0.002~0,01
20~100
200~1000
Scientific notation
1 ×10-5- 1 × 10 -5
2 ×10-5~ 1 × 1n--
2 ×10-+ ~ 1 ×10~3
Minimum value of insulation resistance
7.2.3 If the insulation resistance value is measured at a voltage of 500V and is not stable at a value equal to or higher than the insulation requirement after 2 minutes, a lower test voltage may be used. Alternatively, the insulation resistance may be determined by an indirect method. 7.2.4 If the required insulation resistance cannot be obtained, the manufacturer shall state the minimum insulation resistance value that may be obtained and the maximum source resistance on which the potentiometer is designed to operate. 7.3 Selection switch for measured circuits
The selection switch for measured circuits (if any) shall be installed so that all unselected measured circuits are completely isolated. When the switch is actuated, several measured circuits should not be connected together, even for an instant. 7. 4 Adjustment of potentiometers
If the potentiometers are to be adjusted for correct operation or for standard purposes, they shall be smooth and continuous in operation and shall have fine adjustment so that the potentiometer current can be adjusted with a resolution less than or equal to 10% of the corresponding grade index. 7.5 Temperature limits for storage, transportation and use Unless otherwise specified by the manufacturer, the potentiometers shall be able to withstand exposure to ambient temperatures of -10 to 50°C without damage. After returning to reference conditions, the potentiometers shall meet the requirements of the above standards. Note: ① If the potentiometer is installed on a rack or test bench, care should be taken to ensure that the ventilation of the working area is not blocked. If the potentiometer has a built-in standard battery or other device that will be damaged by temperature changes, the manufacturer may specify other temperature values. 8 Data, signs and symbols
8.1 Data
8.1.1 The manufacturer shall provide the following data: a. Name or trademark of the manufacturer (or the responsible supplier); b. Model number given by the manufacturer (or the responsible supplier); c. Serial number; e. Effective range, resolution and range factor of measurement, grade barrier; c. Reference value and standard value of temperature if different from those given in Tables 1 and 2. g.
If necessary, the main parameters of auxiliary equipment, especially the voltage reference source and current source equipment, should be given; the nominal voltage or nominal voltage range of the auxiliary power supply (if any); the nominal frequency or nominal frequency range of the auxiliary power supply (if any): 1. Standardization and use procedures of the potentiometer; if the insulation resistance value is less than the value specified in Table 4 (see 7.2.4) and the maximum source resistance applicable to correct operation: i. Circuit diagram, list of components and replaceable parts: fly. If the influencing quantity is different from that given in Tables 1 and 2, the reference value (range) and nominal use range of other influencing factors (see f and g) should be given:
1 Test voltage.
8.1.2 If the verification certificate is provided by the manufacturer or the responsible supplier in consultation with the user, it shall include the following information: verification value and its uncertainty;
verification month;
name of the verification unit.
8.2 Markings, symbols and their positions
Markings and symbols shall be clear, easy to read and not easily erased. The symbols specified in 5 shall be used.
8.2.1 The following information shall be marked on the nameplate or housing: a, b, c, C (using the symbols of E-5, E-7 or E-8), g (using the symbols of D-1 to D-6) in 8.1.
In addition, the following marking shall be made:
"DC potentiometer" or this term expressed in other languages. If necessary, the symbol F·33 indicates some other necessary information given in a separate document. If the reference value or reference range is marked, the word should be underlined for easy identification. 8.2.2 All terminals are marked with polarity (if necessary), function and power characteristics. In particular, markings should be made near the following terminals for better identification: measurement terminal:
Terminal for connecting auxiliary equipment
Grounding terminal, if any (using symbol F-31); c.
d. Leakage current shielding (line) terminal, if any; e: Static acid shielding terminal, if any.
The wiring diagram of the auxiliary power supply should be marked near the auxiliary power supply connector or near the entrance of the auxiliary power supply cord. 8.2.3 The following contents shall be given on the network label or external charger, or in a separate document: d, f, k in Section 8.1. 8.3 Documents
8.3.1 The document should state that a, b, c, h, i, j, d, f, k in Article 8.1 of
GB3927-83
are not marked on the nameplate or casing (see Article 8.2.3). 8.3.2 When providing a verification certificate in accordance with 8.1.2, the following information should be stated: a, 1, c, m, n, 0 in 8.1.
9.4 Example of marking of potentiometer
No1 2 31 5
[n ... -1.1Y,μV) × 1/0.1
In this example, the following information is provided: a.
Direct-current potentiometer
Model: AB .CD
DC potentiometer, model A, B, C, D, number 12345, manufactured by N,N,; grade index: 1 × 0 4;
c. When the range factor is 1:
The effective range is (.1.1V)×1, and the resolution is 10V; when the range factor is 0.1:
The effective range is (α..1.1)×0.1, and the resolution is 1μV: d. Reference value of temperature: 23℃,
The nominal use range is from 13 to 33℃,
Because these values are different from the specified values in Tables 1 and 2, they must be indicated e.
More detailed information is given in another document; the test voltage is 500V.
Table 5 Symbols for marking potentiometers*
A— 4
Instructions for use:
Main units and base multiples and submultiples
1EC23 The original text is: "Most of these symbols are extracted from the table of IEC51+10.\Symbol
A --16
A—17
A—20
A—21
A—24
GB3927—83
Continued Table 5
Celsius
Kilometers
Test voltage 500V
Test voltage greater than 500V (depth 2kV)
Instruments that have not been tested after electrical testing
Use Used chemical position
When the potentiometer is used, it is perpendicular to its support surface kv
GB927-83
Continued Table 6
When the potentiometer is used, it is horizontal with its supporting surface. When the potentiometer is used, the supporting surface is inclined with the horizontal plane at an angle of (for example, 6°)
Example of using the potentiometer according to 1-1
Nominal use range B0*10
Potentiometer according to D一2 Example of use Nominal use range -1+1
Potentiometer according to D 一3 Example of use Nominal use range 45·73
Accuracy level
Express the error level index in scientific notation as a ratio of the reference value (for example 1×10-4) When the allowable error is partially proportional to the reference value and partially proportional to the dial indication, express the error level index in percentage (for example 0.01)
When the allowable error is partially proportional to the reference value and partially proportional to the dial indication or ratio, express the error level in ten thousandths
(for example 00)
...9..-- 0
45 .-0...75
1×10-+
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