CN114923547A - An automatic evaluation device and method for error uncertainty of gas representation value - Google Patents

Abstract

The invention discloses an automatic evaluation device for the error uncertainty of a gas indication value, belonging to the technical field of gas flow detection, comprising an indication value sampler and a display, and is characterized in that it further comprises an electrically connected gas flow standard, a sensor, an error Measurement module, verification information module, uncertainty evaluation module and data cache module, the indication value sampler is used to obtain the indication value of the gas meter, the gas flow standard device is used to obtain the reference value, and the error measurement module is used to calculate and determine the indication value error. Whether the indication error is qualified, the verification information module is used to store the factory parameters of the gas flow standard, the factory parameters of the sensor, the verification object information and the verification scheme information, and the uncertainty evaluation module is used for the uncertainty evaluation of the indicator error. The present invention comprehensively judges whether the gas meter is qualified or not through two indicators of the indication error and the expanded uncertainty of the indication error, and can effectively improve the verification accuracy of the gas meter.

Description

An automatic evaluation device and method for error uncertainty of gas representation value

technical field

The invention relates to the technical field of gas flow detection, in particular to an automatic evaluation device and method for the error uncertainty of a gas representation value.

Background technique

The traditional gas meter's indication display system is realized by a mechanical transmission subsystem and a decimal mechanical counter. The roller of the mechanical counter can accept the gas consumption information transmitted from the output shaft of the transmission subsystem, and perform an adding operation. Add one to the count, and finally realize the recording and storage of gas metering. The indication display system of the electronic gas meter is realized by the electromechanical conversion device and electronic counter installed in the mechanical display system.

After the gas meter is produced, its performance needs to be verified. At present, the negative pressure method critical flow venturi nozzle gas meter verification device is often used, that is, the standard device measures the indication error of the gas meter, and compares the measured indication error with the set value. The maximum allowable error is compared to judge whether the gas meter is qualified. The disadvantage of this method is that the uncertainty of the default indication error is in line with the allowable value, and only the indication error is used to judge whether the gas meter is qualified, so the accuracy is low.

The publication number is CN202092737U, and the Chinese patent document whose announcement date is December 28, 2011 discloses a standard meter gas flow standard device that realizes a self-checking function. A measurement system, a pipeline system, a gas source system and a control system; the standard meter system adopts two types of standard meters, a gas turbine flowmeter and a critical flow Venturi nozzle, and the measurement system includes a critical flow Venturi nozzle assembly, The gas turbine standard meter and the temperature and pressure measuring instrument at the measured flowmeter, as well as the hygrometer and the timer; the pipeline system includes the gas source pipeline, the standard meter pipeline and the measured flowmeter pipeline; the gas The source system takes the atmosphere as the gas source, and adopts a fan or a vacuum pump device; the control system is based on a PC; the gas source system is connected to the standard meter system and the gas flow meter to be tested through the pipeline system , adopt the negative pressure method, use the fan or pump to pump the gas, make the gas continuously pass through the standard meter and the detected gas flowmeter in the same time interval, measure the output value of the two through the measurement system, and control the The system completes all field equipment control, data acquisition and data processing.

The standard meter method gas flow standard device that realizes the self-checking function disclosed in this patent document can realize the self-checking function of the device, and can be used in parallel to realize the expansion of the measurement range of the whole set of devices. However, it is still through the indication error to judge whether the gas meter is qualified or not, and the verification accuracy is low.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned defects of the prior art, the present invention provides an automatic evaluation device and method for the error uncertainty of the gas indication value. The present invention measures the indication value of the measured object and the corresponding reference value through the evaluation device, and can obtain each The indication error of a flow point is evaluated, and its uncertainty is evaluated. Through the indication error and the expanded uncertainty of the indication error, it is possible to comprehensively determine whether the gas meter is qualified or not, which can effectively improve the accuracy of the gas meter verification. .

The present invention is achieved through the following technical solutions:

An automatic evaluation device for the error uncertainty of a gas indication value, comprising an indication value sampler and a display for displaying information, and is characterized in that it also includes an electrically connected gas flow standard device, a sensor, an error measurement module, and a verification information module. , Uncertainty evaluation module and data cache module, the indicated value sampler is used to obtain the indicated value of the gas meter, the gas flow standard device is used to obtain the reference value, and the sensor is used to measure the gas flow parameters of the detection medium and the test environment parameters , the error measurement module is used to calculate the indication error and determine whether the indication error is qualified, and the verification information module is used to store the factory parameters of the gas flow standard device, the factory parameters of the sensor, the verification object information and the verification scheme information, The uncertainty evaluation module is used for the uncertainty evaluation of the indication error, and the data cache module is used for storing internal and external cache data.

The indication sampler includes a time measurement standard, a counter and an indication calculator. The time measurement standard is used to collect and record the duration of the sampling signal, the counter is used to collect the number of records, and the indication calculator is used to calculate the indication.

The sensors include a pressure sensor, a temperature sensor, a differential pressure sensor, a humidity sensor and a crystal oscillator.

The error determination module includes an error calculator and an error determiner. The error calculator uses the measurement data to calculate the indication error; the error determiner receives the indication error and determines whether the indication error is qualified.

The uncertainty evaluation module includes a class A relative uncertainty evaluation module, a class B relative uncertainty evaluation module, a synthesis module and a calculation module, and the class A relative uncertainty module is used to measure the indication error according to multiple repeated measurements. Calculate the A-type relative uncertainty of the correction coefficient; the B-type relative uncertainty evaluation module is used to extract the expanded uncertainty of each parameter according to the certificate information stored in the verification information module, and calculate the sensitivity coefficient and Type B relative uncertainty of the correction factor; the synthesis module is used to calculate the extended uncertainty of the correction factor based on the Type A relative uncertainty of the correction factor and the Type B relative uncertainty of the correction factor; the calculation module is used to calculate the extended uncertainty of the correction factor according to the calculation model Convert the expanded uncertainty of the correction factor to the expanded uncertainty of the indication error.

A method for evaluating the error uncertainty of a gas representation value, characterized in that it comprises the following steps:

a. Repeatedly measure the gas representation value V _ind , calculate the reference value V _ref provided by the standard device by formula 1, and calculate the indication error e by formula 2;

where _Vref is the reference value provided by the standard, η is the leakage coefficient, _Cd is the outflow coefficient of the nozzle, A _* is the throat area of the nozzle, C _* is the flow function of the nozzle, and _p0 is the stagnation upstream of the nozzle Pressure, Z is the gas compression coefficient at the gas meter under test, T is the temperature at the gas meter under test, p is the pressure at the gas meter under test, M is the molar mass of the medium gas, and T ₀ is the hysteresis of the gas upstream of the nozzle. stop temperature, R is the general gas constant, τ is the detection time;

Among them, e is the indication error, V _ind is the gas indication value, and V _ref is the reference value provided by the standard;

b. Calculate the correction coefficient of each measurement by formula 3;

Among them, f _{crt, i} is the correction coefficient of a single measurement, V _{ref, i} is the reference value provided by the standard device for a single measurement, V _{ind, i} is the gas representation value of a single measurement, and e _i is the value in a single measurement Indication error;

c. According to the number of repeated measurements, the Type A relative standard uncertainty ur _{, A} (f _crt ) of the correction factor is calculated by formula 4;

为修正系数n次测量的算术平均值；Among them, u _{r, A} (f _crt ) is the type A relative standard uncertainty of the correction factor, s (f _crt ) is the standard deviation of the correction factor n times of measurement,

is the arithmetic mean of n measurements of the correction factor;

d. Extract the expanded uncertainty of each parameter according to the certificate information stored in the verification information module, divide it by the inclusion factor k to obtain the relative standard uncertainty ur (component _{i )} of each parameter, and calculate the sensitivity coefficient C _ri of all components (component _i ), the B-type relative standard uncertainty _ur (V _ref ) introduced by the standard value measurement is obtained by calculation in formula 5;

Among them, ur (V _ref ) is the B-type relative standard uncertainty introduced by the standard value measurement, C _ri (component _i ) is the sensitivity coefficient of the ith component, and _ur (component _i ) is the relative standard uncertainty of the _ith component standard uncertainty;

e. Calculate the B-type relative standard uncertainty _{ur (V ind )} introduced by the gas representation value;

f. According to the B-type relative standard uncertainty _ur (V _ref ) introduced by the standard value measurement and the B-type relative standard uncertainty _{ur (V ind )} introduced by the gas representation value, the B-type relative standard with the correction factor is synthesized Uncertainty ur _{, B} (f _crt );

g. Calculate the relative composite standard uncertainty ur by combining the type A relative standard uncertainty ur _{, A} (f _crt ) of the correction factor and the type B relative standard uncertainty ur _{, B} (f _crt ) of the correction factor _{, c} (f _crt );

h. Calculate the expanded uncertainty U of the indication error by formula 10;

U=k·(1+e)ur _,c (f _crt ) Equation 10

Among them, U is the expanded uncertainty of the indication error, k is the inclusion factor, e is the indication error, and ur _{, c} (f _crt ) is the relative composite standard uncertainty.

In the step d, the sensitivity coefficient C _ri (component _i ) is calculated by formula 6;

为偏导数；分量_i为泄露系数η、喷嘴的流出系数C_d、喷嘴的喉部面积A_*、喷嘴的流函数C_*、喷嘴上游滞止压力p₀、被检燃气表处的气体压缩系数Z、被检燃气表处的温度T、被检燃气表处的压力p、介质气体的摩尔质量M、喷嘴上游气体的滞止温度T₀、通用气体常数R或检测时间τ。Among them, C _ri (component _i ) is the sensitivity coefficient of the ith component, V _ref is the reference value provided by the standard,

is the partial derivative; component _i is the leakage coefficient η, the outflow coefficient C _d of the nozzle, the throat area A _* of the nozzle, the flow function C _* of the nozzle, the stagnant pressure p ₀ upstream of the nozzle, the gas compression coefficient at the gas meter to be tested Z, the temperature T at the gas meter to be tested, the pressure p at the gas meter to be tested, the molar mass M of the medium gas, the stagnation temperature T ₀ of the gas upstream of the nozzle, the universal gas constant R or the detection time τ.

In the step e, calculating the B-type relative standard uncertainty _{ur (V ind )} introduced by the gas representation value refers to calculating by manual reading or mechanical reading;

When reading manually, the Class B relative standard uncertainty _{ur (V ind )} introduced by the gas representation value is the interval half-width divided by the inclusion factor k;

When mechanical reading, the B-type relative standard uncertainty _{ur (V ind )} introduced by the gas representation value is the expanded uncertainty of each parameter extracted from the certificate information stored in the verification information module divided by the inclusion factor k.

In the step f, the B-type relative standard uncertainty ur of the correction coefficient _{, B} (f _crt ) is calculated by formula 8;

Among them, ur _{, B} (f _crt ) is the B-type relative standard uncertainty of the correction factor, _{ur (V ind )} is the B-type relative standard uncertainty introduced by the gas representation value, and _ur (V _ref ) is the standard Type B relative standard uncertainty introduced by value measurements.

In the step g, the relative synthetic standard uncertainty ur _{, c} (f _crt ) is calculated by formula 9;

Among them, ur _{, c} (f _crt ) is the relative composite standard uncertainty, ur _{, A} (f _crt ) is the type A relative standard uncertainty of the correction factor, ur _{, B} (f _crt ) is the correction factor Type B relative standard uncertainty.

The verification principle that the present invention is applied to the gas meter is as follows:

Under specified conditions, the test medium gas source provides a continuous flow of air, which flows through the gas meter and the evaluation device in series, and then is discharged from the test medium discharge port downstream of the evaluation device.

First, determine the relationship between the standard value obtained by the evaluation device and the displayed value of the gas meter, that is, the measurement process of the displayed value error; through the built-in uncertainty evaluation module, calculate the relative standard uncertainty of type A and type B of the correction coefficient. Relative standard uncertainty; calculate the relative composite standard uncertainty of the correction factor; convert the relative composite standard uncertainty of the correction factor into the expanded uncertainty of the indication error according to the formula derivation; finally, according to the indication error and indication error The expanded uncertainty of the gas meter is evaluated, and the verification result is obtained.

The beneficial effects of the present invention are mainly manifested in the following aspects:

1. In the present invention, the indication value of the measured object and the corresponding reference value are measured by the evaluation device, the indication value error of each flow point can be obtained, and its uncertainty is evaluated. The expanded uncertainty of the two indicators comprehensively determines whether the gas meter is qualified, which can effectively improve the accuracy of the gas meter verification.

2. The present invention, through the built-in uncertainty evaluation module in the evaluation device, can realize the automatic evaluation of the uncertainty of the gas meter in the verification process, reduce the workload of manual calculation of the uncertainty, and reduce the cost.

3. The present invention enables the standard device to generate the error of the gas representation value and at the same time gives the uncertainty evaluation result, comprehensively realizes the performance evaluation and verification of the gas meter, and has higher accuracy.

Description of drawings

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments of the description:

Fig. 1 is the structural block diagram of the automatic evaluation device of the present invention;

Fig. 2 is the flow chart of the uncertainty evaluation method of the present invention;

Labels in the figure: 1. Indication sampler, 2. Display, 3. Gas flow standard, 4. Sensor, 5. Error measurement module, 6. Verification information module, 7. Uncertainty evaluation module, 8. Data buffer Module, 9, Time measurement standard, 10, Counter, 11, Indication calculator, 12, Error calculator, 13, Error determiner, 14, Class A relative uncertainty evaluation module, 15, Class B relative uncertainty Degree evaluation module, 16, synthesis module, 17, calculation module.

Detailed ways

Example 1

Referring to Fig. 1, an automatic evaluation device for the uncertainty of gas indication value error includes an indication value sampler 1 and a display 2 for displaying information, and also includes an electrically connected gas flow standard 3, a sensor 4, and an error determination module 5. The verification information module 6, the uncertainty evaluation module 7 and the data buffer module 8, the indication value sampler 1 is used to obtain the indication value of the gas meter, the gas flow standard device 3 is used to obtain the reference value, the The sensor 4 is used to measure and detect the air flow parameters of the medium and the test environment parameters, the error determination module 5 is used to calculate the indication error and determine whether the indication error is qualified, and the verification information module 6 is used to store the data of the gas flow standard 3. Factory parameters, factory parameters of the sensor 4, verification object information and verification scheme information, the uncertainty evaluation module 7 is used for the uncertainty evaluation of the indication error, and the data cache module 8 is used to store internal and external caches data.

This embodiment is the most basic implementation. By measuring the indication value of the measured object and the corresponding reference value by the evaluation device, the indication error of each flow point can be obtained, and its uncertainty is evaluated. The two indicators of error and expanded uncertainty of indication error comprehensively determine whether the gas meter is qualified, which can effectively improve the accuracy of gas meter verification.

Example 2

Referring to Fig. 1, an automatic evaluation device for the uncertainty of gas indication value error includes an indication value sampler 1 and a display 2 for displaying information, and also includes an electrically connected gas flow standard 3, a sensor 4, and an error determination module 5. The verification information module 6, the uncertainty evaluation module 7 and the data buffer module 8, the indication value sampler 1 is used to obtain the indication value of the gas meter, the gas flow standard device 3 is used to obtain the reference value, the The sensor 4 is used to measure and detect the air flow parameters of the medium and the test environment parameters, the error determination module 5 is used to calculate the indication error and determine whether the indication error is qualified, and the verification information module 6 is used to store the data of the gas flow standard 3. Factory parameters, factory parameters of the sensor 4, verification object information and verification scheme information, the uncertainty evaluation module 7 is used for the uncertainty evaluation of the indication error, and the data cache module 8 is used to store internal and external caches data.

The indication sampler 1 includes a time measurement standard 9, a counter 10 and an indication calculator 11. The time measurement standard 9 is used to collect and record the duration of the sampling signal, the counter 10 is used to collect the number of records, and the indication calculator 11 is used for indication calculation.

The sensor 4 includes a pressure sensor, a temperature sensor, a differential pressure sensor, a humidity sensor and a crystal oscillator.

The error determination module 5 includes an error calculator 12 and an error determiner 13. The error calculator 12 uses the measurement data to calculate the indication error; the error determiner 13 receives the indication error and determines whether the indication error is qualified.

Further, the uncertainty assessment module 7 includes a type A relative uncertainty assessment module 14, a type B relative uncertainty assessment module 15, a synthesis module 16 and a calculation module 17, and the type A relative uncertainty module is used for The type A relative uncertainty of the correction coefficient is calculated from the indication error of repeated measurements; the type B relative uncertainty evaluation module 15 is used to extract the expanded uncertainty of each parameter according to the certificate information stored in the verification information module 6, and Calculate the sensitivity coefficient of each parameter and the B-type relative uncertainty of the correction coefficient according to the calculation formula; the synthesis module 16 is used to calculate the expansion of the correction coefficient according to the A-type relative uncertainty of the correction coefficient and the B-type relative uncertainty of the correction coefficient Uncertainty; the calculation module 17 is used to convert the expanded uncertainty of the correction coefficient into the expanded uncertainty of the indication error according to the calculation model.

This embodiment is a preferred implementation. By building the uncertainty evaluation module 7 in the evaluation device, the automatic evaluation of the uncertainty of the gas meter can be realized in the verification process, thereby reducing the workload of manually calculating the uncertainty and reducing the cost.

Example 3

Referring to Fig. 1 and Fig. 2, a method for evaluating the uncertainty of gas representation value error includes the following steps:

a. Repeatedly measure the gas representation value V _ind , calculate the reference value V _ref provided by the standard device by formula 1, and calculate the indication error e by formula 2;

where _Vref is the reference value provided by the standard, η is the leakage coefficient, _Cd is the outflow coefficient of the nozzle, A _* is the throat area of the nozzle, C _* is the flow function of the nozzle, and _p0 is the stagnation upstream of the nozzle Pressure, Z is the gas compression coefficient at the gas meter under test, T is the temperature at the gas meter under test, p is the pressure at the gas meter under test, M is the molar mass of the medium gas, and T ₀ is the hysteresis of the gas upstream of the nozzle. stop temperature, R is the general gas constant, τ is the detection time;

Among them, e is the indication error, V _ind is the gas indication value, and V _ref is the reference value provided by the standard;

b. Calculate the correction coefficient of each measurement by formula 3;

Among them, f _{crt, i} is the correction coefficient of a single measurement, V _{ref, i} is the reference value provided by the standard device for a single measurement, V _{ind, i} is the gas representation value of a single measurement, and e _i is the value in a single measurement Indication error;

c. According to the number of repeated measurements, the Type A relative standard uncertainty ur _{, A} (f _crt ) of the correction factor is calculated by formula 4;

为修正系数n次测量的算术平均值；Among them, u _{r, A} (f _crt ) is the type A relative standard uncertainty of the correction factor, s (f _crt ) is the standard deviation of the correction factor n times of measurement,

is the arithmetic mean of n measurements of the correction factor;

d. Extract the extended uncertainty of each parameter according to the certificate information stored in the verification information module 6, divide it by the inclusion factor k to obtain the relative standard uncertainty ur (component _{i )} of each parameter, and calculate the sensitivity coefficient C of all components _ri (component _i ), calculated by formula 5 to obtain the B-type relative standard uncertainty _ur (V _ref ) introduced by the standard value measurement;

Among them, ur (V _ref ) is the B-type relative standard uncertainty introduced by the standard value measurement, C _ri (component _i ) is the sensitivity coefficient of the ith component, and _ur (component _i ) is the relative standard uncertainty of the _ith component standard uncertainty;

e. Calculate the B-type relative standard uncertainty _{ur (V ind )} introduced by the gas representation value;

f. According to the B-type relative standard uncertainty _ur (V _ref ) introduced by the standard value measurement and the B-type relative standard uncertainty _{ur (V ind )} introduced by the gas representation value, the B-type relative standard with the correction factor is synthesized Uncertainty ur _{, B} (f _crt );

g. Calculate the relative composite standard uncertainty ur by combining the type A relative standard uncertainty ur _{, A} (f _crt ) of the correction factor and the type B relative standard uncertainty ur _{, B} (f _crt ) of the correction factor _{, c} (f _crt );

h. Calculate the expanded uncertainty U of the indication error by formula 10;

U=k·(1+e)ur _,c (f _crt ) Equation 10

Among them, U is the expanded uncertainty of the indication error, k is the inclusion factor, e is the indication error, and ur _{, c} (f _crt ) is the relative composite standard uncertainty.

In the step d, the sensitivity coefficient C _ri (component _i ) is calculated by formula 6;

为偏导数；分量_i为泄露系数η、喷嘴的流出系数C_d、喷嘴的喉部面积A_*、喷嘴的流函数C_*、喷嘴上游滞止压力p₀、被检燃气表处的气体压缩系数Z、被检燃气表处的温度T、被检燃气表处的压力p、介质气体的摩尔质量M、喷嘴上游气体的滞止温度T₀、通用气体常数R或检测时间τ。Among them, C _ri (component _i ) is the sensitivity coefficient of the ith component, V _ref is the reference value provided by the standard,

is the partial derivative; component _i is the leakage coefficient η, the outflow coefficient C _d of the nozzle, the throat area A _* of the nozzle, the flow function C _* of the nozzle, the stagnant pressure p ₀ upstream of the nozzle, the gas compression coefficient at the gas meter to be tested Z, the temperature T at the gas meter to be tested, the pressure p at the gas meter to be tested, the molar mass M of the medium gas, the stagnation temperature T ₀ of the gas upstream of the nozzle, the universal gas constant R or the detection time τ.

In the step e, calculating the B-type relative standard uncertainty _{ur (V ind )} introduced by the gas representation value refers to calculating by manual reading or mechanical reading;

When reading manually, the Class B relative standard uncertainty _{ur (V ind )} introduced by the gas representation value is the interval half-width divided by the inclusion factor k;

When mechanically read, the B-type relative standard uncertainty _{ur (V ind )} introduced by the gas representation value is the expanded uncertainty of each parameter extracted from the certificate information stored in the verification information module 6 divided by the inclusion factor k.

In the step f, the B-type relative standard uncertainty ur of the correction coefficient _{, B} (f _crt ) is calculated by formula 8;

Among them, ur _{, B} (f _crt ) is the B-type relative standard uncertainty of the correction factor, _{ur (V ind )} is the B-type relative standard uncertainty introduced by the gas representation value, and _ur (V _ref ) is the standard Type B relative standard uncertainty introduced by value measurements.

In the step g, the relative synthetic standard uncertainty ur _{, c} (f _crt ) is calculated by formula 9;

Among them, ur _{, d} (f _crt ) is the relative composite standard uncertainty, ur _{, A} (f _crt ) is the type A relative standard uncertainty of the correction factor, ur _{, B} (f _crt ) is the correction factor Type B relative standard uncertainty.

This embodiment is the best implementation, and the evaluation method of the present invention is adopted, so that the standard device generates the error of the gas representation value and gives the uncertainty evaluation result, comprehensively realizes the performance evaluation and verification of the gas meter, and has higher accuracy.

The verification process that the present invention is applied to the gas meter is as follows:

When the expanded uncertainty U (k=2) of the indication error is not greater than one-third of the absolute value of the maximum allowable error in the corresponding flow range, that is, U≤1/3 MPEV, the criterion is:

|e|≤MPEV judged as qualified

|e|＞MPEV is judged to be unqualified

When the expanded uncertainty U of the indication error is greater than one-third of the absolute value of the maximum allowable error in the corresponding flow range, that is, U>1/3 MPEV,

The domestic judgment standard is:

|e|≤MPEV-U judged as qualified

|e|≥MPEV+U judged as unqualified

MPEV-U＜|e|＜MPEV+U judged as pending

The international judgment standard is:

According to the provisions of Article 11.1.2 of OIML R 137-1&2:2012 "Gas Meter", the maximum allowable error can be reduced under the premise of satisfying U≤MPEV, and the maximum allowable error MPE can be narrowed to MPE _reduction = ±(4/3 MPEV -U), that is:

e≤±(4/3·MPEV-U) judged as qualified

e>±(4/3·MPEV-U) It is judged as unqualified.

Claims (10)

1. An automatic assessment device for gas indicating value error uncertainty, which comprises an indicating value sampler (1) and a display (2) for displaying information, and is characterized in that: also comprises a gas flow standard device (3), a sensor (4), an error measuring module (5), a verification information module (6), an uncertainty evaluation module (7) and a data cache module (8) which are electrically connected, the indicating value sampler (1) is used for obtaining the indicating value of the gas meter, the gas flow standard device (3) is used for obtaining a reference value, the sensor (4) is used for measuring the air flow parameter of the detection medium and the test environment parameter, the error determination module (5) is used for calculating the indicating error and judging whether the indicating error is qualified or not, the verification information module (6) is used for storing factory parameters of the gas flow standard device (3), factory parameters of the sensor (4), verification object information and verification scheme information, the uncertainty evaluation module (7) is used for evaluating the uncertainty of the indication error, and the data caching module (8) is used for storing internal and external cached data.

2. The automatic evaluation device for the uncertainty of the gas-indicating value error according to claim 1, characterized in that: the indicating value sampler (1) comprises a time measurement standard device (9), a counter (10) and an indicating value calculator (11), wherein the time measurement standard device (9) is used for collecting and recording the duration of sampling signals, the counter (10) is used for collecting and recording the number of the sampling signals, and the indicating value calculator (11) is used for indicating value calculation.

3. A gas meter value error uncertainty automatic assessment apparatus according to claim 1, characterized in that: the sensor (4) comprises a pressure sensor, a temperature sensor, a differential pressure sensor, a humidity sensor and a crystal oscillator.

4. A gas meter value error uncertainty automatic assessment apparatus according to claim 1, characterized in that: the error determination module (5) comprises an error calculator (12) and an error determiner (13), wherein the error calculator (12) calculates an indication error by using the measurement data; an error determiner (13) receives the indication error and determines whether the indication error is acceptable.

5. The automatic evaluation device for the uncertainty of the gas-indicating value error according to claim 1, characterized in that: the uncertainty evaluation module (7) comprises an A-type relative uncertainty evaluation module (14), a B-type relative uncertainty evaluation module (15), a synthesis module (16) and a calculation module (17), wherein the A-type relative uncertainty module is used for calculating the A-type relative uncertainty of the correction coefficient according to the indicating value errors of repeated measurement; the B-type relative uncertainty evaluation module (15) is used for extracting the expansion uncertainty of each parameter according to the certificate information stored in the verification information module (6), and calculating the B-type relative uncertainty of the sensitivity coefficient and the correction coefficient of each parameter according to a calculation formula; the synthesis module (16) is used for calculating the expansion uncertainty of the correction coefficient according to the A-type relative uncertainty of the correction coefficient and the B-type relative uncertainty of the correction coefficient; the calculation module (17) is used for converting the expansion uncertainty of the correction coefficient into the expansion uncertainty of the indicating value error according to the calculation model.

6. A gas meter indication value error uncertainty evaluation method is characterized by comprising the following steps: the method comprises the following steps:

a. repeatedly measuring gas indicating value V _ind Calculating the reference magnitude V provided by the standard device by equation 1 _ref Calculating an indicating value error e by using the formula 2;

wherein, V _ref Reference value provided for the etalon, η being the leakage coefficient, C _d Is the discharge coefficient of the nozzle, A _* Is the throat area of the nozzle, C _* As a function of the flow of the nozzle, p ₀ Is the nozzle upstream stagnation pressure, Z is the gas compression coefficient at the gas meter under test, T is the temperature at the gas meter under test, p is the pressure at the gas meter under test, M is the molar mass of the dielectric gas, T is the gas pressure at the gas meter under test ₀ Is the stagnation temperature of the gas upstream of the nozzle, R is the universal gas constant, and τ is the detection time;

wherein e is an indication error，V _ind For indicating the value, V, of the gas meter _ref A reference magnitude provided for a standard;

b. calculating a correction coefficient of each measurement according to the formula 3;

wherein, f _crt，i Correction factor, V, for a single measurement _ref，i Reference value, V, provided for a single measurement standard _ind，i For a single measurement of the gas indication, e _i Indicating value error in single measurement;

c. calculating the A-type relative standard uncertainty u of the correction coefficient according to the repeated measurement times by the formula 4 _r，A (f _crt )；

Wherein u is _r，A (f _crt ) Class A relative standard uncertainty, s (f), for correction factor _crt ) To correct for the standard deviation of the coefficient n measurements,

is the arithmetic mean of the correction factor n measurements;

d. extracting the expansion uncertainty of each parameter according to certificate information stored in a verification information module (6), and dividing the expansion uncertainty by an inclusion factor k to obtain the relative standard uncertainty u of each parameter _r (component (C) _i ) Calculating the sensitivity coefficient C of all components _ri (component (s)) _i ) And calculating and obtaining the B-type relative standard uncertainty u introduced by standard value measurement through formula 5 _r (V _ref )；

Wherein u is _r (V _ref ) Class B relative Standard uncertainty introduced for Standard value measurements, C _ri (component (s)) _i ) Is the sensitivity coefficient of the i-th component, u _r (component (s)) _i ) Relative standard uncertainty for the ith component;

e. calculating the uncertainty u of B-type relative standard introduced by the gas indicating value _r (V _ind )；

f. Measuring the introduced class B relative standard uncertainty u according to the standard value _r (V _ref ) And B-class relative standard uncertainty u introduced by gas indicating value _r (V _ind ) And synthesizing the B-type relative standard uncertainty u of the correction coefficient _r，B (f _crt )；

g. Class A relative standard uncertainty u in combination with correction factor _r，A (fcrt) and class B relative Standard uncertainty of correction factor u _r，B (f _crt ) Calculating relative synthesis standard uncertainty u _r，c (f _crt )；

h. Calculating the expansion uncertainty U of the indicating value error by the formula 10;

U＝k·(1+e)u _r，c (f _crt ) Formula 10

Wherein U is the expansion uncertainty of the indicating error, k is the inclusion factor, e is the indicating error, U _r，c (f _crt ) Relative synthesis standard uncertainty.

7. A gas meter value error uncertainty assessment method according to claim 6, characterized in that: in said step d, the sensitivity coefficient C _ri (component (s)) _i ) Calculating by the formula 6;

wherein, C _ri (component (C) _i ) Is the sensitivity coefficient of the i-th component, V _ref The reference quantity value provided for the etalon,

is a partial derivative; component(s) of _i Is leakage coefficient eta, discharge coefficient C of nozzle _d Throat area A of the nozzle _* Flow function of nozzle C _* Nozzle upstream stagnation pressure p ₀ Gas compression coefficient Z of gas to be tested, temperature T of gas to be tested, pressure p of gas to be tested, molar mass M of medium gas, stagnation temperature T of gas at upstream of nozzle ₀ Universal gas constant R or detection time τ.

8. A gas meter value error uncertainty assessment method according to claim 6, characterized in that: in the step e, calculating the type B relative standard uncertainty u introduced by the gas indicating value _r (V _ind ) The method comprises the steps of calculating according to manual reading or mechanical reading;

when manual reading is carried out, the type B relative standard uncertainty u introduced by the gas indicating value _r (V _ind ) Is the interval half-width divided by the inclusion factor k;

when mechanical reading is carried out, the type B relative standard uncertainty u introduced by the gas indicating value _r (V _ind ) The extended uncertainty of each parameter is extracted for certificate information stored in a certification information module (6) divided by an inclusion factor k.

9. The method of claim 6, wherein the method comprises the following steps: in said step f, the class B relative standard uncertainty u of the correction factor _r，B (f _crt ) Calculating by equation 8;

wherein u is _r，B (f _crt ) For correction of the B-type relative standard uncertainty, u, of the coefficient _r (V _ind ) Class B relative standard uncertainty, u, introduced for gas meter readings _r (V _ref ) Introduction of class B relative Standard uncertainty for Standard value measurementAnd (5) determining the degree.

10. A gas meter value error uncertainty assessment method according to claim 6, characterized in that: in said step g, relative synthesis standard uncertainty u _r，c (f _crt ) Calculated by equation 9;

wherein u is _r，c (f _crt ) For relative synthesis standard uncertainty, u _r，A (f _crt ) Class A relative standard uncertainty, u, for correction factor _r，B (f _crt ) Is the class B relative standard uncertainty of the correction factor.

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