This standard applies to the initial calibration, subsequent calibration and in-use inspection of the series of spring tube type general pressure gauges, pressure vacuum gauges and vacuum gauges with a measuring range upper limit of (-0.1 to 1000) MPa. JJG 52-1999 Verification Procedure for Spring Tube Type General Pressure Gauges, Pressure Vacuum Gauges and Vacuum Gauges JJG52-1999 Standard download decompression password: www.bzxz.net
This standard applies to the initial calibration, subsequent calibration and in-use inspection of the series of spring tube type general pressure gauges, pressure vacuum gauges and vacuum gauges with a measuring range upper limit of (-0.1 to 1000) MPa.

National Metrology Verification Regulation of the People's Republic of China JJG52-1999
Bourdon Tube Pressure Gauge, Pressure-Vacuum GaugeandVacuum GaugeforGeneralUse
1999-12-22 Issued
2000-04-01 Implementation
State Administration of Quality and Technical Supervision Issued
JJG52—1999
Verification Regulation of Bourdon Tube Pressure Gauge, Pressure-Vacuum GaugeandVacuum GaugeforGeneral UseJJG52—1999
Replace JJG52—1987
JJG337—1983
This regulation was approved by the State Administration of Quality and Technical Supervision on December 22, 1999, and will be implemented on April 1, 2000.
Responsible unit: National Pressure Metrology Technical Committee Main drafting unit: Shanghai Testing Technology Institute Shanghai Institute of Metrology and Testing Technology
Participating drafting unit: Zhejiang Hongqi Instrument Factory Shanghai Testing Technology Institute
This regulation is entrusted to the National Pressure Metrology Technical Committee for interpretation Main drafters of this regulation:
Xuan Jiarong
Dai Xiaohua
Participating drafters:
Zhou Fanglong
Dai Gendi
JJG52-1999
(Shanghai Testing Technology Institute)
(Shanghai Institute of Metrology and Testing Technology) (Zhejiang Hongqi Instrument Factory)
(Shanghai Testing Technology Institute)
1 Scope·
2 Overview
3 Metrological performance requirements
JJG52—1999
3.1 Accuracy grade and allowable error of pressure gauge3.2 Indication error
3.3 Return error
3.4 ​​Tap displacement
3.5 Pointer deflection stability:
4 General technical requirements
Appearance·||tt| |4.2 Zero position·
5 Control of measuring instruments
First calibration, subsequent calibration and inspection during use5.2 Calibration conditions
Calibration items and calibration methods
5.4 Processing of calibration results:
5.5 Calibration cycle·
Appendix A
Appendix B
Basic format of pressure gauge calibration record
Inner page format of pressure gauge calibration failure noticeAppendix C
List of calculated values ​​of allowable error of pressure gauge
(1)
(2)|| tt||：（2）
（2）
（3）
（3）
（4）
JJG52—1999
Verification Procedure for Bourdon-Tube General Pressure Gauges, Pressure Vacuum Gauges and Vacuum Gauges This procedure refers to the International Recommendation No. 101 of the International Organization of Legal Metrology "Pressure Gauges, Vacuum Gauges and Pressure Vacuum Gauges (General Instruments) with Elastic Sensing Elements", adopts some contents that conform to my country's national conditions, and retains the effective contents of the original regulations JJG52—1987 and JJG337—1983. 1 Scope
This procedure applies to the initial verification, subsequent verification and in-use inspection of the series of bourdon-tube general pressure gauges, pressure vacuum gauges and vacuum gauges (hereinafter referred to as pressure gauges) with an upper limit of the measuring range of (-0.1～1000)MPa. 2 Overview
Pressure gauges are mainly used for the measurement of liquid, gas and vapor pressure and vacuum. The working principle of the pressure gauge is that the spring tube produces elastic deformation under the action of pressure and vacuum, causing the displacement of the tube end. The displacement is amplified by the mechanical transmission mechanism and transmitted to the indicating device. The pointer then indicates the measured pressure or vacuum value on the dial engraved with the legal measurement unit. 3 Measurement performance requirements
3.1 Accuracy grade and allowable error of pressure gauge The accuracy grade and allowable error of pressure gauge and their relationship are shown in Table 1. Table 1
Allowable error% (calculated as a percentage of the range)Accuracy grade
1.6 (1.5)
With stop pinWww.bzxZ.net
Without stop pin
Upper limit of measurement
(90~100)%
Note: The allowable error of the 1.5-level pressure gauge in use is calculated as 1.6-level, and the accuracy grade can be unchanged. 3.2 Indication error
Within the measurement range, the indication error should not be greater than the allowable error specified in Table 1. 3.3 Return error
The rest
JJG52--1999
Within the measuring range, the return error shall not be greater than the absolute value of the allowable error specified in Table 1. 3.4 Tap displacement
After tapping the case, the change in the pointer indication shall not be greater than 1/2 of the absolute value of the allowable error specified in Table 1. 3.5 Pointer deflection stability
Within the measuring range, the pointer deflection shall be stable without jumping or jamming. 4 General technical requirements
4.1 Appearance
4.1.1 Appearance
4.1.1.1 The parts of the pressure gauge shall be firmly assembled without looseness. 4.1.1.2 The coating of the newly manufactured pressure gauge shall be uniform and smooth without obvious peeling. 4.1.1.3 The pressure gauge shall be equipped with a safety hole, and a dustproof device shall be provided on the safety hole (except for the pressure gauge that does not allow the measured medium to escape from the gauge).
4.1.1.4 The pressure gauge shall have the color code specified in Table 2 according to the medium it measures, and indicate the name of the special medium. The oxygen gauge must also be marked with the red "Oil Free" word. Table 2
Pressure Measuring Medium
Other Combustible Gases
Other Inert Gases or Liquids
4.1.2 Markings
The following markings shall be on the dividing plate: manufacturing unit or trademark; product name; measurement unit and number; measuring instrument manufacturing license mark and number; vacuum shall have "_" or "minus"; accuracy grade; factory number. 4.1.3 Reading Part
4.1.3.1 The gauge glass shall be colorless and transparent, and shall not have defects and damage that hinder reading. 2
JJG52—1999
4.1.3.2 The dividing plate shall be flat and smooth, and each mark shall be clearly identifiable. 4.1.3.3 The pointer indication end should be able to cover 1/3 to 2/3 of the length of the shortest graduation line. 4.1.3.4 The width of the pointer indication end should not be greater than the width of the graduation line. 4.1.4 Measurement upper limit value number
The measurement upper limit value number should conform to one of the following series: 1×10n, 1.6×10\, 2.5×10\, 4×10\, 6×10\. Where: n is a positive integer, a negative integer or zero. 4.1.5 Graduation value
The graduation value should conform to one of the following series: 1×10″, 2×10″, 5×10
Where: n is a positive integer, a negative integer or zero. 4.1.6 Accuracy level
1, 1.6,, 2.5, 4.
4.2 Zero position
4.2.1 For pressure gauges with stop pins, when there is no pressure or vacuum, the pointer should be close to the stop pin, and the "shrinkage" should not exceed the absolute value of the allowable error specified in Table 1.
4.2.2 For pressure gauges without stop pins, when there is no pressure or vacuum, the pointer should be within the zero position mark, and the zero position mark should not exceed twice the absolute value of the allowable error specified in Table 1. 5 Control of measuring instruments
5.1 Initial calibration, subsequent calibration and in-use inspection The metrological performance and technical requirements of pressure gauges for initial calibration, subsequent calibration and in-use inspection shall comply with the requirements of 3.1 to 3.5 and 4.1 to 4.2 of this regulation.
5.2 Verification conditions
5.2.1 Standard instrument
5.2.1.1 Error requirements for standard instrument
The absolute value of the allowable error of the standard instrument should not be greater than 1/4 of the absolute value of the allowable error of the pressure gauge being tested. 5.2.1.2 The standard instruments available for selection are as follows: a) Spring tube precision pressure gauge and vacuum gauge; b) Piston pressure gauge;
c) Piston pressure vacuum gauge;
d) Liquid pressure gauge;
e) Other pressure measurement standards that meet the error requirements of the standard instrument. 5.2.2 The auxiliary equipment available for selection are as follows: 5.2.2.1 Pressure calibrator, vacuum calibrator; 5.2.2.2 Hand-lift pump, electric pump, vacuum pump; 5.2.2.3 Oil-gas, oil-water isolator; 3
5.2.2.4 Electric contact signal transmission equipment;
JJG52—1999
5.2.2.5 High resistance meter: 500V.DC, Class 2.5; 5.2.2.6 Safety cover for ultra-high pressure meter. 5.2.3 Environmental conditions
5.2.3.1 Environmental temperature: (20±5)℃
5.2.3.2 Environmental relative humidity: not more than 85%5.2.3.3 Environmental pressure: atmospheric pressure
5.2.3.4 The pressure gauge should be left to stand for at least 2 hours under the environmental conditions of 5.3.3.1, 5.3.3.2, and 5.3.3.3 before calibration. 5.2.4 Calibration working medium
5.2.4.1 For pressure gauges with a measuring upper limit not exceeding 0.25MPa, the working medium shall be clean air or non-toxic, harmless and chemically stable gas.
5.2.4.2 The working medium of the pressure gauge with the upper measuring limit of (0.25250) MPa is non-corrosive liquid. 5.2.4.3 The working medium of the pressure gauge with the upper measuring limit of (400～1000) MPa is a mixture of medicinal glycerin and ethylene glycol or the working medium required by the standard instrument. 5.3 Verification items and verification methods
5.3.1 Appearance
Observe visually and it shall meet the requirements of 4.1. 5.3.2 Zero position
Observe visually and it shall meet the requirements of 4.2. 5.3.3 Verification of indication error, return error and tapping displacement 5.3.3.1 When the standard instrument and the pressure gauge use liquid as the working medium, their pressure points shall be basically on the same horizontal plane. If they are not on the same horizontal plane, the pressure error caused by the height difference of the liquid column shall be considered. 5.3.3.2 The indication of the pressure gauge shall be estimated according to 1/5 of the scale value. 5.3.3.3 Verification method of indication
The indication verification of the pressure gauge is carried out according to the graduation line marked with numbers. During the verification, the pressure is gradually and steadily increased (or decreased). When the indication reaches the upper limit of measurement, the pressure source (or vacuum source) is cut off, the pressure is withstood for 3 minutes, and then the pressure is steadily decreased (or increased) according to the original verification point and the inspection is carried out in reverse order.
5.3.3.4 Error of indication
For each verification point, during the verification of increasing (or decreasing) and decreasing (or increasing) pressure, the difference between the indication before and after tapping the case and the indication of the standard instrument shall meet the requirements of 3.2. 5.3.3.5 Return error
For the same verification point, during the verification of increasing (or decreasing) and decreasing (or increasing) pressure, the difference between the indication after tapping the case shall meet the requirements of 3.3.
5.3.3.6 Tap displacement
For each calibration point, during the pressure increase (or pressure reduction) and pressure reduction (or pressure increase) calibration, the indication change caused by tapping the case shall meet the requirements of 3.4.
5.3.3.7 Pointer deflection stability
JJG52—1999
During the indication error calibration process, the deflection of the pointer is observed visually and shall meet the requirements of 3.5. 5.3.4 Calibration of the vacuum part of the pressure vacuum gauge 5.3.4.1 The upper limit of pressure measurement is (0.3~2.4)MPa. Vacuum part calibration: The pointer should be able to point to the vacuum direction when evacuated.
5.3.4.2 The upper limit of pressure measurement is 0.15MPa, and the vacuum part calibration is two-point indication. 5.3.4.3 The upper limit of pressure measurement is 0.06MPa, and the vacuum part calibration is three-point indication. 5.3.4.4 The vacuum gauge shall be tested for pressure resistance according to the porosity of more than 90% of the local atmospheric pressure. 5.3.5 Additional verification of several pressure gauges
5.3.5.1 Grease-free inspection of oxygen pressure gauge In order to ensure safety, a grease-free inspection shall be carried out before and after the indication verification. The inspection method is: pour pure warm boiled water into the spring tube, shake it, and throw the water into the container filled with clean water. If there is no colored oil shadow on the water surface, it is considered to be grease-free.
5.3.5.2 Verification of pressure gauge with inspection pointer First, the inspection pointer and the indicating pointer shall be verified at the same time, and the readings shall be recorded. Then the indicating pointer shall be returned to zero position, and the indicating pointer shall be verified again. The difference between the two pressure increase indications at each verification point shall not be greater than the absolute value of the allowable error. During the indication verification, the inspection pointer shall not move when the case is tapped. 5.3.5.3 Verification of double-needle double-tube or double-needle single-tube pressure gauges First check the connectivity of the two tubes of the double-needle double-tube pressure gauge. The two tubes should not be connected. The inspection method is: install one of the joints on the calibrator, pressurize to the upper limit of measurement, and the pointer should point to the upper limit of measurement; the other pointer should be at zero position, and there should be no oil leakage on the other joint at this time, that is, the two tubes are not connected. Then install the pressure gauge through the three-way joint for indication verification. The difference between the indications of the two pointers of the double-needle double-tube or double-needle single-tube pressure gauge should also be checked. The difference should not be greater than the absolute value of the allowable error. The two pointers should not affect each other.
For easy identification, the two joints should be painted with the same color as the two pointers. 5.3.5.4 Verification of electric contact pressure gauge
a) Insulation resistance test
Use a high resistance meter with a DC working voltage of 500V to connect between the terminal and the shell of the electric contact pressure gauge. When measuring, the reading should be stable for 10s and should not be less than 20MQ (ambient temperature is 15℃～35C, relative humidity is not more than 80%).
b) Set point deviation and switching difference verification
For each set point, the set point deviation verification should be carried out in both the pressure increase and pressure decrease states. 1-The upper limit is set at two points near 50% and 75% of the range, and the lower limit is set at two points near 25% and 50% of the range.
Make the setting pointer at the set value, and increase or decrease the pressure steadily and slowly (the speed of the indicating pointer approaching the set value should not exceed 1% of the range per second) until the signal is connected or disconnected and is positive. The pressure value read on the standard is the upper switching value or the lower switching value.
-Set point deviation
The difference between the indication of the set point (i.e., the set value) and the pressure value when the signal switches shall comply with the provisions of Table 3. 5
Accuracy level
1.6 (1.5)
Switching difference
JJG52—1999
Allowable value of set point deviation% (calculated as a percentage of the range) Direct-acting type
Magnetic-assisted direct-acting type
±0.5~±4
At the same set point, the difference between the actual pressure values ​​when the pressure gauge signal is connected and disconnected (when switching) shall comply with the following provisions:
Direct-acting type, shall not be greater than the absolute value of the allowable error of the indication: Magnetic-assisted direct-acting type, shall not be greater than 3.5% of the range. 5.4 Handling of verification results
5.4.1 A "verification certificate" will be issued to pressure gauges that pass the verification, and the qualified accuracy level will be given on the certificate. Pressure gauges used for mandatory verification are sealed with a mark. 5.4.2 A "verification failure notice" will be issued to pressure gauges that fail the verification, and the unqualified items and contents will be indicated (see Appendix B).
5.5 Verification cycle
The verification cycle of pressure gauges generally does not exceed half a year. 6
Appendix A
Inspection unit
Name of pressure gauge
Manufacturer
Factory number
Appearance inspection
Standard pressure
Remarks:
JJG52—1999
Basic format of pressure gauge calibration record
Pressure gauge calibration record
, calibration date
, measurement range Ambient
Calibration temperature
Allowable error
, graduation value
, allowable error of standard instrument
Indication of the meter under test after tapping
Calibration result: Conforms to
Grade review:
Change in pointer after tapping
Year,
Calibrator:
Note: When the calibration record is used for full performance testing, relevant content may be added as appropriate. Date
Return error
Year/Month/Day
Appendix B
Name of calibration standard:
Accuracy grade:
Factory number:
Calibration temperature:
Unqualified items and contents:
JJG52—1999
Inner page format of pressure gauge calibration failure notice2 The working medium of the pressure gauge with a measuring upper limit of (0.25250) MPa is a non-corrosive liquid. 5.2.4.3 The working medium of the pressure gauge with a measuring upper limit of (400-1000) MPa is a mixture of medicinal glycerin and ethylene glycol or the working medium required by the standard instrument. 5.3 Verification items and verification methods
5.3.1 Appearance
Observe visually and it shall meet the requirements of 4.1. 5.3.2 Zero position
Observe visually and it shall meet the requirements of 4.2. 5.3.3 Verification of indication error, return error and tapping displacement5.3.3.1 When the standard instrument and the pressure gauge use liquid as the working medium, their pressure points should be basically on the same horizontal plane. If they are not on the same horizontal plane, the pressure error caused by the height difference of the liquid column should be considered. 5.3.3.2 The indication of the pressure gauge should be estimated according to 1/5 of the scale value. 5.3.3.3 Verification method of indication
The indication verification of the pressure gauge is carried out according to the graduation line marked with numbers. During the verification, the pressure is gradually and steadily increased (or decreased). When the indication reaches the upper limit of measurement, the pressure source (or vacuum source) is cut off, the pressure is withstood for 3 minutes, and then the pressure is steadily decreased (or increased) according to the original verification point and the inspection is carried out in reverse order.
5.3.3.4 Error of indication
For each verification point, during the verification of increasing (or decreasing) and decreasing (or increasing) pressure, the difference between the indication before and after tapping the case and the indication of the standard instrument shall meet the requirements of 3.2. 5.3.3.5 Return error
For the same verification point, during the verification of increasing (or decreasing) and decreasing (or increasing) pressure, the difference between the indication after tapping the case shall meet the requirements of 3.3.
5.3.3.6 Tap displacement
For each calibration point, during the pressure increase (or pressure reduction) and pressure reduction (or pressure increase) calibration, the indication change caused by tapping the case shall meet the requirements of 3.4.
5.3.3.7 Pointer deflection stability
JJG52—1999
During the indication error calibration process, the deflection of the pointer is observed visually and shall meet the requirements of 3.5. 5.3.4 Calibration of the vacuum part of the pressure vacuum gauge 5.3.4.1 The upper limit of pressure measurement is (0.3~2.4)MPa. Vacuum part calibration: The pointer should be able to point to the vacuum direction when evacuated.
5.3.4.2 The upper limit of pressure measurement is 0.15MPa, and the vacuum part calibration is two-point indication. 5.3.4.3 The upper limit of pressure measurement is 0.06MPa, and the vacuum part calibration is three-point indication. 5.3.4.4 The vacuum gauge shall be tested for pressure resistance according to the porosity of more than 90% of the local atmospheric pressure. 5.3.5 Additional verification of several pressure gauges
5.3.5.1 Grease-free inspection of oxygen pressure gauge In order to ensure safety, a grease-free inspection shall be carried out before and after the indication verification. The inspection method is: pour pure warm boiled water into the spring tube, shake it, and throw the water into the container filled with clean water. If there is no colored oil shadow on the water surface, it is considered to be grease-free.
5.3.5.2 Verification of pressure gauge with test pointer First, the test pointer and the indicating pointer shall be tested for indication at the same time, and the readings shall be recorded. Then the indicating pointer shall be returned to zero position, and the indicating pointer shall be tested for indication again. The difference between the two pressure increase indications at each verification point shall not be greater than the absolute value of the allowable error. During the indication verification, the test pointer shall not move when the case is tapped. 5.3.5.3 Verification of double-needle double-tube or double-needle single-tube pressure gauges First check the connectivity of the two tubes of the double-needle double-tube pressure gauge. The two tubes should not be connected. The inspection method is: install one of the joints on the calibrator, pressurize to the upper limit of measurement, and the pointer should point to the upper limit of measurement; the other pointer should be at zero position, and there should be no oil leakage on the other joint at this time, that is, the two tubes are not connected. Then install the pressure gauge through the three-way joint for indication verification. The difference between the indications of the two pointers of the double-needle double-tube or double-needle single-tube pressure gauge should also be checked. The difference should not be greater than the absolute value of the allowable error. The two pointers should not affect each other.
For easy identification, the two joints should be painted with the same color as the two pointers. 5.3.5.4 Verification of electric contact pressure gauge
a) Insulation resistance test
Use a high resistance meter with a DC working voltage of 500V to connect between the terminal and the shell of the electric contact pressure gauge. When measuring, the reading should be stable for 10s and should not be less than 20MQ (ambient temperature is 15℃～35C, relative humidity is not more than 80%).
b) Set point deviation and switching difference verification
For each set point, the set point deviation verification should be carried out in both the pressure increase and pressure decrease states. 1-The upper limit is set at two points near 50% and 75% of the range, and the lower limit is set at two points near 25% and 50% of the range.
Make the setting pointer at the set value, and increase or decrease the pressure steadily and slowly (the speed of the indicating pointer approaching the set value should not exceed 1% of the range per second) until the signal is connected or disconnected and is positive. The pressure value read on the standard is the upper switching value or the lower switching value.
-Set point deviation
The difference between the indication of the set point (i.e., the set value) and the pressure value when the signal switches shall comply with the provisions of Table 3. 5
Accuracy level
1.6 (1.5)
Switching difference
JJG52—1999
Allowable value of set point deviation% (calculated as a percentage of the range) Direct-acting type
Magnetic-assisted direct-acting type
±0.5~±4
At the same set point, the difference between the actual pressure values ​​when the pressure gauge signal is connected and disconnected (when switching) shall comply with the following provisions:
Direct-acting type, shall not be greater than the absolute value of the allowable error of the indication: Magnetic-assisted direct-acting type, shall not be greater than 3.5% of the range. 5.4 Handling of verification results
5.4.1 A "verification certificate" will be issued to pressure gauges that pass the verification, and the qualified accuracy level will be given on the certificate. Pressure gauges used for mandatory verification are also sealed. 5.4.2 A "verification failure notice" will be issued to pressure gauges that fail the verification, and the unqualified items and contents will be indicated (see Appendix B).
5.5 Verification cycle
The verification cycle of pressure gauges is generally not more than half a year. 6
Appendix A
Inspection unit
Name of pressure gauge
Manufacturer
Factory number
Appearance inspection
Standard pressure
Remarks:
JJG52—1999
Basic format of pressure gauge calibration record
Pressure gauge calibration record
, calibration date
, measurement range Ambient
Calibration temperature
Allowable error
, graduation value
, allowable error of standard instrument
Indication of the meter under test after tapping
Calibration result: Conforms to
Grade review:
Change in pointer after tapping
Year,
Calibrator:
Note: When the calibration record is used for full performance testing, relevant content may be added as appropriate. Date
Return error
Year/Month/Day
Appendix B
Name of calibration standard:
Accuracy grade:
Factory number:
Calibration temperature:
Unqualified items and contents:
JJG52—1999
Inner page format of pressure gauge calibration failure notice2 The working medium of the pressure gauge with a measuring upper limit of (0.25250) MPa is a non-corrosive liquid. 5.2.4.3 The working medium of the pressure gauge with a measuring upper limit of (400-1000) MPa is a mixture of medicinal glycerin and ethylene glycol or the working medium required by the standard instrument. 5.3 Verification items and verification methods
5.3.1 Appearance
Observe visually and it shall meet the requirements of 4.1. 5.3.2 Zero position
Observe visually and it shall meet the requirements of 4.2. 5.3.3 Verification of indication error, return error and tapping displacement5.3.3.1 When the standard instrument and the pressure gauge use liquid as the working medium, their pressure points should be basically on the same horizontal plane. If they are not on the same horizontal plane, the pressure error caused by the height difference of the liquid column should be considered. 5.3.3.2 The indication of the pressure gauge should be estimated according to 1/5 of the scale value. 5.3.3.3 Verification method of indication
The indication verification of the pressure gauge is carried out according to the graduation line marked with numbers. During the verification, the pressure is gradually and steadily increased (or decreased). When the indication reaches the upper limit of measurement, the pressure source (or vacuum source) is cut off, the pressure is withstood for 3 minutes, and then the pressure is steadily decreased (or increased) according to the original verification point and the inspection is carried out in reverse order.
5.3.3.4 Error of indication
For each verification point, during the verification of increasing (or decreasing) and decreasing (or increasing) pressure, the difference between the indication before and after tapping the case and the indication of the standard instrument shall meet the requirements of 3.2. 5.3.3.5 Return error
For the same verification point, during the verification of increasing (or decreasing) and decreasing (or increasing) pressure, the difference between the indication after tapping the case shall meet the requirements of 3.3.
5.3.3.6 Tap displacement
For each calibration point, during the pressure increase (or pressure reduction) and pressure reduction (or pressure increase) calibration, the indication change caused by tapping the case shall meet the requirements of 3.4.
5.3.3.7 Pointer deflection stability
JJG52—1999
During the indication error calibration process, the deflection of the pointer is observed visually and shall meet the requirements of 3.5. 5.3.4 Calibration of the vacuum part of the pressure vacuum gauge 5.3.4.1 The upper limit of pressure measurement is (0.3~2.4)MPa. Vacuum part calibration: The pointer should be able to point to the vacuum direction when evacuated.
5.3.4.2 The upper limit of pressure measurement is 0.15MPa, and the vacuum part calibration is two-point indication. 5.3.4.3 The upper limit of pressure measurement is 0.06MPa, and the vacuum part calibration is three-point indication. 5.3.4.4 The vacuum gauge shall be tested for pressure resistance according to the porosity of more than 90% of the local atmospheric pressure. 5.3.5 Additional verification of several pressure gauges
5.3.5.1 Grease-free inspection of oxygen pressure gauge In order to ensure safety, a grease-free inspection shall be carried out before and after the indication verification. The inspection method is: pour pure warm boiled water into the spring tube, shake it, and throw the water into the container filled with clean water. If there is no colored oil shadow on the water surface, it is considered to be grease-free.
5.3.5.2 Verification of pressure gauge with inspection pointer First, the inspection pointer and the indicating pointer shall be verified at the same time, and the readings shall be recorded. Then the indicating pointer shall be returned to zero position, and the indicating pointer shall be verified again. The difference between the two pressure increase indications at each verification point shall not be greater than the absolute value of the allowable error. During the indication verification, the inspection pointer shall not move when the case is tapped. 5.3.5.3 Verification of double-needle double-tube or double-needle single-tube pressure gauges First check the connectivity of the two tubes of the double-needle double-tube pressure gauge. The two tubes should not be connected. The inspection method is: install one of the joints on the calibrator, pressurize to the upper limit of measurement, and the pointer should point to the upper limit of measurement; the other pointer should be at zero position, and there should be no oil leakage on the other joint at this time, that is, the two tubes are not connected. Then install the pressure gauge through the three-way joint for indication verification. The difference between the indications of the two pointers of the double-needle double-tube or double-needle single-tube pressure gauge should also be checked. The difference should not be greater than the absolute value of the allowable error. The two pointers should not affect each other.
For easy identification, the two joints should be painted with the same color as the two pointers. 5.3.5.4 Verification of electric contact pressure gauge
a) Insulation resistance test
Use a high resistance meter with a DC working voltage of 500V to connect between the terminal and the shell of the electric contact pressure gauge. When measuring, the reading should be stable for 10s and should not be less than 20MQ (ambient temperature is 15℃～35C, relative humidity is not more than 80%).
b) Set point deviation and switching difference verification
For each set point, the set point deviation verification should be carried out in both the pressure increase and pressure decrease states. 1-The upper limit is set at two points near 50% and 75% of the range, and the lower limit is set at two points near 25% and 50% of the range.
Make the setting pointer at the set value, and increase or decrease the pressure steadily and slowly (the speed of the indicating pointer approaching the set value should not exceed 1% of the range per second) until the signal is connected or disconnected and is positive. The pressure value read on the standard is the upper switching value or the lower switching value.
-Set point deviation
The difference between the indication of the set point (i.e., the set value) and the pressure value when the signal switches shall comply with the provisions of Table 3. 5
Accuracy level
1.6 (1.5)
Switching difference
JJG52—1999
Allowable value of set point deviation% (calculated as a percentage of the range) Direct-acting type
Magnetic-assisted direct-acting type
±0.5~±4
At the same set point, the difference between the actual pressure values ​​when the pressure gauge signal is connected and disconnected (when switching) shall comply with the following provisions:
Direct-acting type, shall not be greater than the absolute value of the allowable error of the indication: Magnetic-assisted direct-acting type, shall not be greater than 3.5% of the range. 5.4 Handling of verification results
5.4.1 A "verification certificate" will be issued to pressure gauges that pass the verification, and the qualified accuracy level will be given on the certificate. Pressure gauges used for mandatory verification are sealed with a mark. 5.4.2 A "verification failure notice" will be issued to pressure gauges that fail the verification, and the unqualified items and contents will be indicated (see Appendix B).
5.5 Verification cycle
The verification cycle of pressure gauges generally does not exceed half a year. 6
Appendix A
Inspection unit
Name of pressure gauge
Manufacturer
Factory number
Appearance inspection
Standard pressure
Remarks:
JJG52—1999
Basic format of pressure gauge calibration record
Pressure gauge calibration record
, calibration date
, measurement range Ambient
Calibration temperature
Allowable error
, graduation value
, allowable error of standard instrument
Indication of the meter under test after tapping
Calibration result: Conforms to
Grade review:
Change in pointer after tapping
Year,
Calibrator:
Note: When the calibration record is used for full performance testing, relevant content may be added as appropriate. Date
Return error
Year/Month/Day
Appendix B
Name of calibration standard:
Accuracy grade:
Factory number:
Calibration temperature:
Unqualified items and contents:
JJG52—1999
Inner page format of pressure gauge calibration failure notice3.6 Tap displacement
For each calibration point, during the pressure increase (or pressure reduction) and pressure reduction (or pressure increase) calibration, the indication change caused by tapping the case shall meet the requirements of 3.4.
5.3.3.7 Pointer deflection stability
JJG52—1999
During the indication error calibration process, the deflection of the pointer is observed visually and shall meet the requirements of 3.5. 5.3.4 Calibration of the vacuum part of the pressure vacuum gauge 5.3.4.1 The upper limit of pressure measurement is (0.3~2.4)MPa. Vacuum part calibration: The pointer should be able to point to the vacuum direction when evacuated.
5.3.4.2 The upper limit of pressure measurement is 0.15MPa, and the vacuum part calibration is two-point indication. 5.3.4.3 The upper limit of pressure measurement is 0.06MPa, and the vacuum part calibration is three-point indication. 5.3.4.4 The vacuum gauge shall be tested for pressure resistance according to the porosity of more than 90% of the local atmospheric pressure. 5.3.5 Additional verification of several pressure gauges
5.3.5.1 Grease-free inspection of oxygen pressure gauge In order to ensure safety, a grease-free inspection shall be carried out before and after the indication verification. The inspection method is: pour pure warm boiled water into the spring tube, shake it, and throw the water into the container filled with clean water. If there is no colored oil shadow on the water surface, it is considered to be grease-free.
5.3.5.2 Verification of pressure gauge with inspection pointer First, the inspection pointer and the indicating pointer shall be verified at the same time, and the readings shall be recorded. Then the indicating pointer shall be returned to zero position, and the indicating pointer shall be verified again. The difference between the two pressure increase indications at each verification point shall not be greater than the absolute value of the allowable error. During the indication verification, the inspection pointer shall not move when the case is tapped. 5.3.5.3 Verification of double-needle double-tube or double-needle single-tube pressure gauges First check the connectivity of the two tubes of the double-needle double-tube pressure gauge. The two tubes should not be connected. The inspection method is: install one of the joints on the calibrator, pressurize to the upper limit of measurement, and the pointer should point to the upper limit of measurement; the other pointer should be at zero position, and there should be no oil leakage on the other joint at this time, that is, the two tubes are not connected. Then install the pressure gauge through the three-way joint for indication verification. The difference between the indications of the two pointers of the double-needle double-tube or double-needle single-tube pressure gauge should also be checked. The difference should not be greater than the absolute value of the allowable error. The two pointers should not affect each other.
For easy identification, the two joints should be painted with the same color as the two pointers. 5.3.5.4 Verification of electric contact pressure gauge
a) Insulation resistance test
Use a high resistance meter with a DC working voltage of 500V to connect between the terminal and the shell of the electric contact pressure gauge. When measuring, the reading should be stable for 10s and should not be less than 20MQ (ambient temperature is 15℃～35C, relative humidity is not more than 80%).
b) Set point deviation and switching difference verification
For each set point, the set point deviation verification should be carried out in both the pressure increase and pressure decrease states. 1-The upper limit is set at two points near 50% and 75% of the range, and the lower limit is set at two points near 25% and 50% of the range.
Make the setting pointer at the set value, and increase or decrease the pressure steadily and slowly (the speed of the indicating pointer approaching the set value should not exceed 1% of the range per second) until the signal is connected or disconnected and is positive. The pressure value read on the standard is the upper switching value or the lower switching value.
-Set point deviation
The difference between the indication of the set point (i.e., the set value) and the pressure value when the signal switches shall comply with the provisions of Table 3. 5
Accuracy level
1.6 (1.5)
Switching difference
JJG52—1999
Allowable value of set point deviation% (calculated as a percentage of the range) Direct-acting type
Magnetic-assisted direct-acting type
±0.5~±4
At the same set point, the difference between the actual pressure values ​​when the pressure gauge signal is connected and disconnected (when switching) shall comply with the following provisions:
Direct-acting type, shall not be greater than the absolute value of the allowable error of the indication: Magnetic-assisted direct-acting type, shall not be greater than 3.5% of the range. 5.4 Handling of verification results
5.4.1 A "verification certificate" will be issued to pressure gauges that pass the verification, and the qualified accuracy level will be given on the certificate. Pressure gauges used for mandatory verification are also sealed. 5.4.2 A "verification failure notice" will be issued to pressure gauges that fail the verification, and the unqualified items and contents will be indicated (see Appendix B).
5.5 Verification cycle
The verification cycle of pressure gauges is generally not more than half a year. 6
Appendix A
Inspection unit
Name of pressure gauge
Manufacturer
Factory number
Appearance inspection
Standard pressure
Remarks:
JJG52—1999
Basic format of pressure gauge calibration record
Pressure gauge calibration record
, calibration date
, measurement range Ambient
Calibration temperature
Allowable error
, graduation value
, allowable error of standard instrument
Indication of the meter under test after tapping
Calibration result: Conforms to
Grade review:
Change in pointer after tapping
Year,
Calibrator:
Note: When the calibration record is used for full performance testing, relevant content may be added as appropriate. Date
Return error
Year/Month/Day
Appendix B
Name of calibration standard:
Accuracy grade:
Factory number:
Calibration temperature:
Unqualified items and contents:
JJG52—1999
Inner page format of pressure gauge calibration failure notice3.6 Tap displacement
For each calibration point, during the pressure increase (or pressure reduction) and pressure reduction (or pressure increase) calibration, the indication change caused by tapping the case shall meet the requirements of 3.4.
5.3.3.7 Pointer deflection stability
JJG52—1999
During the indication error calibration process, the deflection of the pointer is observed visually and shall meet the requirements of 3.5. 5.3.4 Calibration of the vacuum part of the pressure vacuum gauge 5.3.4.1 The upper limit of pressure measurement is (0.3~2.4)MPa. Vacuum part calibration: The pointer should be able to point to the vacuum direction when evacuated.
5.3.4.2 The upper limit of pressure measurement is 0.15MPa, and the vacuum part calibration is two-point indication. 5.3.4.3 The upper limit of pressure measurement is 0.06MPa, and the vacuum part calibration is three-point indication. 5.3.4.4 The vacuum gauge shall be tested for pressure resistance according to the porosity of more than 90% of the local atmospheric pressure. 5.3.5 Additional verification of several pressure gauges
5.3.5.1 Grease-free inspection of oxygen pressure gauge In order to ensure safety, a grease-free inspection shall be carried out before and after the indication verification. The inspection method is: pour pure warm boiled water into the spring tube, shake it, and throw the water into the container filled with clean water. If there is no colored oil shadow on the water surface, it is considered to be grease-free.
5.3.5.2 Verification of pressure gauge with inspection pointer First, the inspection pointer and the indicating pointer shall be verified at the same time, and the readings shall be recorded. Then the indicating pointer shall be returned to zero position, and the indicating pointer shall be verified again. The difference between the two pressure increase indications at each verification point shall not be greater than the absolute value of the allowable error. During the indication verification, the inspection pointer shall not move when the case is tapped. 5.3.5.3 Verification of double-needle double-tube or double-needle single-tube pressure gauges First check the connectivity of the two tubes of the double-needle double-tube pressure gauge. The two tubes should not be connected. The inspection method is: install one of the joints on the calibrator, pressurize to the upper limit of measurement, and the pointer should point to the upper limit of measurement; the other pointer should be at zero position, and there should be no oil leakage on the other joint at this time, that is, the two tubes are not connected. Then install the pressure gauge through the three-way joint for indication verification. The difference between the indications of the two pointers of the double-needle double-tube or double-needle single-tube pressure gauge should also be checked. The difference should not be greater than the absolute value of the allowable error. The two pointers should not affect each other.
For easy identification, the two joints should be painted with the same color as the two pointers. 5.3.5.4 Verification of electric contact pressure gauge
a) Insulation resistance test
Use a high resistance meter with a DC working voltage of 500V to connect between the terminal and the shell of the electric contact pressure gauge. When measuring, the reading should be stable for 10s and should not be less than 20MQ (ambient temperature is 15℃～35C, relative humidity is not more than 80%).
b) Set point deviation and switching difference verification
For each set point, the set point deviation verification should be carried out in both the pressure increase and pressure decrease states. 1-The upper limit is set at two points near 50% and 75% of the range, and the lower limit is set at two points near 25% and 50% of the range.
Make the setting pointer at the set value, and increase or decrease the pressure steadily and slowly (the speed of the indicating pointer approaching the set value should not exceed 1% of the range per second) until the signal is connected or disconnected and is positive. The pressure value read on the standard is the upper switching value or the lower switching value.
-Set point deviation
The difference between the indication of the set point (i.e., the set value) and the pressure value when the signal switches shall comply with the provisions of Table 3. 5
Accuracy level
1.6 (1.5)
Switching difference
JJG52—1999
Allowable value of set point deviation% (calculated as a percentage of the range) Direct-acting type
Magnetic-assisted direct-acting type
±0.5~±4
At the same set point, the difference between the actual pressure values ​​when the pressure gauge signal is connected and disconnected (when switching) shall comply with the following provisions:
Direct-acting type, shall not be greater than the absolute value of the allowable error of the indication: Magnetic-assisted direct-acting type, shall not be greater than 3.5% of the range. 5.4 Handling of verification results
5.4.1 A "verification certificate" will be issued to pressure gauges that pass the verification, and the qualified accuracy level will be given on the certificate. Pressure gauges used for mandatory verification are also sealed. 5.4.2 A "verification failure notice" will be issued to pressure gauges that fail the verification, and the unqualified items and contents will be indicated (see Appendix B).
5.5 Verification cycle
The verification cycle of pressure gauges is generally not more than half a year. 6
Appendix A
Inspection unit
Name of pressure gauge
Manufacturer
Factory number
Appearance inspection
Standard pressure
Remarks:
JJG52—1999
Basic format of pressure gauge calibration record
Pressure gauge calibration record
, calibration date
, measurement range Ambient
Calibration temperature
Allowable error
, graduation value
, allowable error of standard instrument
Indication of the meter under test after tapping
Calibration result: Conforms to
Grade review:
Change in pointer after tapping
Year,
Calibrator:
Note: When the calibration record is used for full performance testing, relevant content may be added as appropriate. Date
Return error
Year/Month/Day
Appendix B
Name of calibration standard:
Accuracy grade:
Factory number:
Calibration temperature:
Unqualified items and contents:
JJG52—1999
Inner page format of pressure gauge calibration failure notice4 Verification of electric contact pressure gauge
a) Insulation resistance test
Use a high resistance meter with a DC working voltage of 500V to connect between the terminal and the shell of the electric contact pressure gauge. When measuring, the reading should be stable for 10s and should not be less than 20MQ (ambient temperature is 15℃～35C, relative humidity is not more than 80%).
b) Set point deviation and switching difference verification
For each set point, the set point deviation verification should be carried out in both the boost and de-boost states. 1-The upper limit is set at two points near 50% and 75% of the range, and the lower limit is set at two points near 25% and 50% of the range.
Make the setting pointer at the set value, and increase or decrease the pressure steadily and slowly (the speed of the indicating pointer approaching the set value should not be greater than 1% of the range per second) until the signal is connected or disconnected and is positive. The pressure value read on the standard is the upper switching value or the lower switching value.
-Set point deviation
The difference between the indication of the set point (i.e., the set value) and the pressure value when the signal switches shall comply with the provisions of Table 3. 5
Accuracy level
1.6 (1.5)
Switching difference
JJG52—1999
Allowable value of set point deviation% (calculated as a percentage of the range) Direct-acting type
Magnetic-assisted direct-acting type
±0.5~±4
At the same set point, the difference between the actual pressure values ​​when the pressure gauge signal is connected and disconnected (when switching) shall comply with the following provisions:
Direct-acting type, shall not be greater than the absolute value of the allowable error of the indication: Magnetic-assisted direct-acting type, shall not be greater than 3.5% of the range. 5.4 Handling of verification results
5.4.1 A "verification certificate" will be issued to pressure gauges that pass the verification, and the qualified accuracy level will be given on the certificate. Pressure gauges used for mandatory verification are also sealed. 5.4.2 A "verification failure notice" will be issued to pressure gauges that fail the verification, and the unqualified items and contents will be indicated (see Appendix B).
5.5 Verification cycle
The verification cycle of pressure gauges is generally not more than half a year. 6
Appendix A
Inspection unit
Name of pressure gauge
Manufacturer
Factory number
Appearance inspection
Standard pressure
Remarks:
JJG52—1999
Basic format of pressure gauge calibration record
Pressure gauge calibration record
, calibration date
, measurement range Ambient
Calibration temperature
Allowable error
, graduation value
, allowable error of standard instrument
Indication of the meter under test after tapping
Calibration result: Conforms to
Grade review:
Change in pointer after tapping
Year,
Calibrator:
Note: When the calibration record is used for full performance testing, relevant content may be added as appropriate. Date
Return error
Year/Month/Day
Appendix B
Name of calibration standard:
Accuracy grade:
Factory number:
Calibration temperature:
Unqualified items and contents:
JJG52—1999
Inner page format of pressure gauge calibration failure notice4 Verification of electric contact pressure gauge
a) Insulation resistance test
Use a high resistance meter with a DC working voltage of 500V to connect between the terminal and the shell of the electric contact pressure gauge. When measuring, the reading should be stable for 10s and should not be less than 20MQ (ambient temperature is 15℃～35C, relative humidity is not more than 80%).
b) Set point deviation and switching difference verification
For each set point, the set point deviation verification should be carried out in both the boost and de-boost states. 1-The upper limit is set at two points near 50% and 75% of the range, and the lower limit is set at two points near 25% and 50% of the range.
Make the setting pointer at the set value, and increase or decrease the pressure steadily and slowly (the speed of the indicating pointer approaching the set value should not be greater than 1% of the range per second) until the signal is connected or disconnected and is positive. The pressure value read on the standard is the upper switching value or the lower switching value.
-Set point deviation
The difference between the indication of the set point (i.e., the set value) and the pressure value when the signal switches shall comply with the provisions of Table 3. 5
Accuracy level
1.6 (1.5)
Switching difference
JJG52—1999
Allowable value of set point deviation% (calculated as a percentage of the range) Direct-acting type
Magnetic-assisted direct-acting type
±0.5~±4
At the same set point, the difference between the actual pressure values ​​when the pressure gauge signal is connected and disconnected (when switching) shall comply with the following provisions:
Direct-acting type, shall not be greater than the absolute value of the allowable error of the indication: Magnetic-assisted direct-acting type, shall not be greater than 3.5% of the range. 5.4 Handling of verification results
5.4.1 A "verification certificate" will be issued to pressure gauges that pass the verification, and the qualified accuracy level will be given on the certificate. Pressure gauges used for mandatory verification are also sealed. 5.4.2 A "verification failure notice" will be issued to pressure gauges that fail the verification, and the unqualified items and contents will be indicated (see Appendix B).
5.5 Verification cycle
The verification cycle of pressure gauges is generally not more than half a year. 6
Appendix A
Inspection unit
Name of pressure gauge
Manufacturer
Factory number
Appearance inspection
Standard pressure
Remarks:
JJG52—1999
Basic format of pressure gauge calibration record
Pressure gauge calibration record
, calibration date
, measurement range Ambient
Calibration temperature
Allowable error
, graduation value
, allowable error of standard instrument
Indication of the meter under test after tapping
Calibration result: Conforms to
Grade review:
Change in pointer after tapping
Year,
Calibrator:
Note: When the calibration record is used for full performance testing, relevant content may be added as appropriate. Date
Return error
Year/Month/Day
Appendix B
Name of calibration standard:
Accuracy grade:
Factory number:
Calibration temperature:
Unqualified items and contents:
JJG52—1999
Inner page format of pressure gauge calibration failure notice
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