Some standard content:
National Metrology Verification Regulation of the People's Republic of China JJG272-2007
Aneroid Barometer & Aneroid Barograph2007-06-14Promulgated
Implementation on 2007-12-14
The General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China issued JJG272--2007
Aneroid Barometer & Aneroid Barograph
Verification Regulation of
Aneroid Barometer&Aneroid BarographJJG272-—2007
Replaces JJG272—1991
This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on June 14, 2007, and came into effect on December 14, 2007.
Responsible unit: National Pressure Metrology Technical Committee Main drafting unit: Zhejiang Meteorological Instrument Verification Institute Participating drafting unit: Guangdong Meteorological Metrology Verification Institute This regulation entrusts the National Pressure Metrology Technical Committee to be responsible for the interpretation of this regulation Main drafters:
JJG272—2007
Shituan production box air taste table production food air
Caibaojin
Sheng Yousheng (Zhejiang Meteorological Instrument Verification Institute) Luo Chang (Zhejiang Meteorological Instrument Verification Institute) participated in the drafting Person:
Luo Huaijie (Guangdong Meteorological Metrology Verification Institute) Hhgonie
ornnab
Guo Xing Medical
Huitong Cantong Guoquan Single Mouth Day
Play Fee Haoxue Xiang Single Grass Huisheng
Tuibao Catch Selling Outside: Body Single Ton
Tonghuizhan Zero Sealing Ya Trial Guoquan
Scope·
2 Overview·
Metering Performance Requirements·
General Technical Requirements·
4.1 Appearance requirements·
4.2 Other requirements·
5 Control of measuring instruments
Verification conditions.
Verification items
5.3 Verification methods
5.4 Processing of verification results
Verification cycle·
JJG272—2007
Appendix A Verification record form format for barometer and barometer temperature coefficient Appendix BD Verification method for normal pressure domain of type YJ1 empty box barometer Appendix C Verification of pressure indication value Format of calibration record table Appendix D Format of calibration record table for barometer indication Appendix E Format of calibration record table for supplementary correction value of barometer Format of inner page of calibration certificate
Appendix F
Appendix G Format of inner page of calibration result notice
1 Scope
JJG272-—2007
Calibration procedures for empty box barometer and empty box barometer
This procedure applies to the initial calibration, subsequent calibration and in-use inspection of empty box barometer and empty box barometer. 2 Overview
Empty box barometer and empty box barometer are instruments used to measure atmospheric pressure. The working principle of the empty box barometer is to use the elastic deformation of the diaphragm box caused by the atmospheric pressure, which is converted into the corresponding pointer rotation through the transmission mechanism to measure the atmospheric pressure. Empty box barometers are generally divided into precision empty box barometers, ordinary empty box barometers and plateau empty box barometers. The working principle of the empty box barometer is to use the elastic deformation of the diaphragm box under the action of atmospheric pressure, and through the transmission mechanism conversion, the self-recording pen tip records the corresponding air pressure value on the time-pressure coordinate recording paper, forming a time-pressure recording curve to measure the atmospheric pressure. The empty box barometer is divided into two types according to the recording period: diary type and weekly type. 3 Metrological performance requirements
The metrological performance requirements of barometers and barometers are shown in Table 1. Table 1 Requirements for measurement performance
Instrument name
Empty box gas
Empty box gas
Empty box gas
Barometer
Measuring range
800~1060
800-1060
500-1060
500--1030
Within the range of 870～
1050
(or within the range of 600～
1060)
The measuring range can be taken as any
90 range
integer 10hPa point indication
correction value/hPa
in the measurement range
the lower limit shall not exceed
±1.4, and the remaining points
shall not exceed±1.2
shall not exceed 2.5
shall not exceed 4.0
When the error of the midpoint
of the pen position is 0.0
, the upper and lower limits of the measurement range
shall not exceed
the indication between adjacent 10hPa points
|tt||The variable of correction value/hPa
In the range of 830~1030
, it shall not exceed ±0.5, and in the rest range
, it shall not exceed ±1.0
In the range of 830~1030
, it shall not exceed ±0.5, and in the rest range
, it shall not exceed ±1.0
In the range of 550~1030
, it shall not exceed ±1.3, and in the rest range
, it shall not exceed ±0.7
Temperature system Number
shall not exceed
shall not exceed
shall not exceed
shall not exceed
supplementary correction
positive value/hPa
shall not exceed
shall not exceed
shall not exceed
4 General technical requirements
4.1 Appearance requirements
JJG272-—2007
General gas dining and sanitary products Zhongcheng Guang Old Home 4.1.1 All parts of the empty box barometer and empty box barometer should be assembled correctly and firmly, and the connection should be reliable. 4.1.2 The appearance of the empty box barometer and empty box barometer should be clean. The appearance of the newly manufactured empty box barometer and empty box barometer should be smooth, and the protective layer should not have defects such as shedding, scratches, and rust. 4.1.3 The nameplate shall indicate the instrument name, model specification, manufacturer name, year of manufacture, and factory number, and shall be clearly legible.
4.1.4 The glass panel of the empty box barometer shall be transparent and clean, and shall not have bubbles, air filaments, sand particles, scratches, refracted light, or other defects that hinder reading.
4.1.5 The surface of the dial of the empty box barometer shall be flat, clean, and uniform in color. The scale lines and characters shall be clear and distinct and arranged in a centripetal direction. The scale lines shall be clearly distinguished in length and weighed. The characters shall be neat and correctly positioned. The measuring range and graduation value shall be indicated on the dial.
4.1.6 The pointer of the empty box barometer shall be straight and shall not touch the glass and dial at any position. The blade at the end of the pointer shall be perpendicular to the dial and shall be able to cover 1/4 to 2/3 of the shortest scale line on the dial. Its width shall not be greater than the width of the scale line.
4.2 Other requirements
4.2.1 Requirements for empty box barometers
4.2.1.1 When the adjustment screw is turned, the pointer should be able to move flexibly and smoothly. When the adjustment screw is turned in the forward and reverse directions, the displacement of the pointer should not be less than 30hPa.
4.2.1.2 When the empty box barometer is placed flat, tap the table body lightly, and the pointer displacement is not greater than 1/2 of the scale value. 4.2.1.3 When the flat empty box barometer is tilted 45° in any direction, the pointer displacement is not greater than 1/2 of the scale value.
4.2.1.4 The scale range of the auxiliary temperature meter of the empty box barometer is -11.0℃～41.0℃, and the maximum allowable error is ±1.0℃.
4.2.2 Requirements for empty box barometers
4.2.2.1 The transmission system should be correct and flexible, and the adjustment screw of the pen holder should rotate flexibly. When the adjustment screw is turned, the transmission system should be able to make the self-recording pen tip move smoothly up and down on the self-recording paper throughout the entire process, and its drawing line can match the arc time line on the self-recording paper. The offset of the mismatch shall not exceed 1/3 (diary type) or 1/4 (weekly type) of the distance between two adjacent time marks.
4.2.2.2 When the external air pressure state is changed, the steps formed by the pen tip drawing line on the self-recording paper due to the gap and friction of the transmission system shall not be greater than 0.5hPa. 4.2.2.3 The pen holder shall be straight, smooth and elastic. The pen tip shall draw lines on the self-recording paper smoothly, without scratching the paper or breaking the line, and the width of the line shall not be greater than 0.3mm.
4.2.2.4 The pen guard shall be able to move inward and outward smoothly. When moving outward, the pen tip shall be able to leave the self-recording paper by not less than 4mm and not touch the shell; when moving inward, it shall leave the pen holder by not less than 2mm. 4.2.2.5 The lock on the housing should be able to be locked and opened flexibly. 4.2.2.6 The self-recording clock shall be used after verification. 2
5 Control of measuring instruments
JJG272—2007
Control of measuring instruments includes initial verification, subsequent verification and in-use inspection. 5.1 Verification conditionsbzxZ.net
5.1.1 Environmental conditions
The laboratory shall avoid direct sunlight, excessive air flow and large vibration, and the indoor temperature fluctuation shall not exceed ±2℃.
5.1.2 Standard instrument
A celestial instrument with a maximum allowable error of ±0.4h or other barometric standard instrument with reasonable accuracy. 5.1.3 Auxiliary equipment 5.1.3.1 The indication calibration instrument has the energy of increasing and decreasing pressure required for indication calibration and has good air tightness. Its leakage rate is within 10mir. 5.1.3.2 The fluctuation of temperature coefficient is not large. The air bed shall not change. The true value is %.5℃, and the average accuracy error is ±0.3℃. 5.1.3.3 Maximum 5.2 Calibration items Calibration items Technical requirements 1.00 Standard thermometer Source: lighting device for low-power lighting 35)℃ two temperature adjustment ranges; the atmospheric pressure in the calibration box and the atmospheric pressure in the temperature box are connected to each other. NHO
Verification Items
Barometer
Temperature Coefficient Verification
Indication Verification
Supplementary Correction Verification
Note: "+" indicates items to be inspected
5.3 Verification Methods
Barometer
Continued Verification
Barometer
Indicates items that may not be inspected.
METROLOG
5.3.1 Appearance Requirements Visual inspection shall be conducted in accordance with 4.1. 5.3.2 General Technical Requirements For the inspection methods of each item in 4.2, see Table 3. Barometer
Table 3 General technical requirements 4.2 Inspection methods Clauses
4.2.1.2, 4.2.1.3
Inspection methods
Inspection in use
Barometer
Slowly turn the adjustment screw forward and backward to observe the movement of the pointer and check the displacement of the pointer. Lay the barometer flat, tap the body and tilt it 45° to observe the displacement of the pointer. Use the pressure adjustment screw to adjust the pen tip to the desired position. Check the upper and lower end points of the recording paper and the arc drawn by the pen tip
4.2.2.3,4.2.2.4
JJG272-—2007
Table 3 (continued)
Checking method
First adjust the pen tip to the middle point and rotate the clock to check the horizontal line drawn by the pen tip on the self-recording paper: then gently lift or press the pen handle to make the pen tip leave the horizontal line (10~15)hPa, and check the position where the pen tip returns after releasing the pen handle. Check the upper and lower end points in the same way, visually inspect and measure with a millimeter ruler
Do the opening and closing inspection
Check the calibration certificate of the self-recording clock
5.3.3 When reading the empty box barometer, you need to tap the body of the meter to eliminate the friction of the instrument transmission parts before reading. At the beginning of the calibration of the empty box barometer, the self-recording clock must be fully wound, the self-recording paper must be installed, and the self-recording pen tip must be aligned with the time. 5.3.4 Verification of temperature coefficient
5.3.4.1 The empty box barometer and empty box barometer that have been inspected for appearance can be calibrated for temperature coefficient. When starting the temperature coefficient calibration, the barometer pointer and the barometer pen tip should be adjusted to a position that is no more than ±0.5hPa away from the current standard value of air pressure. If the difference between the indicated air pressure value and the standard value of air pressure is no more than 3hPa during subsequent calibration and inspection during use, this adjustment is not required. Then put the standard thermometer and the empty box barometer or empty box barometer into the temperature coefficient calibration box.
5.3.4.2 The temperature coefficient calibration is carried out at any point within the two temperature ranges of (05)℃ and (25~35)℃ (i.e., low and high temperature points). The order of the two temperature points can be selected arbitrarily, but the temperature difference must be greater than 20℃. 5.3.4.3 During the whole process of temperature coefficient verification, the atmospheric pressure change shall not exceed 3hPac5.3.4.4 Under low and high temperature conditions, the stabilization time of the empty box barometer or empty box barometer in the temperature coefficient verification box shall not be less than 2h.
5.3.4.5 Under low and high temperature conditions, read the pressure value of the pressure standard, the temperature value of the standard thermometer and the pressure indication of the empty box barometer and empty box barometer respectively. The pressure value of the pressure standard is accurate to 0.1hPa, and the temperature value of the standard thermometer is accurate to 0.1℃; the pressure indication of the empty box barometer is estimated to 0.1hPa, and the pressure indication of the empty box barometer is recorded by drawing a line, and it will be estimated to 0.1hPa after the temperature coefficient verification is completed. 5.3.5 Data processing of temperature coefficient verification
5.3.5.1 The format of the temperature coefficient verification record sheet is shown in Appendix A. 5.3.5.2 Subtract the pressure value of the standard instrument (after correction of the indication) from the pressure indication of the barometer or barometer to obtain the pressure difference for comparison.
5.3.5.3 The temperature coefficient K is calculated using formula (1): K, = Ap, - Ap2
(hPa/℃, rounded to two decimal places)
Where: Api
At the high temperature point, the pressure difference between the standard pressure value and the pressure indication of the empty box barometer or empty box barometer, hPa
At the low temperature point, the pressure difference between the standard pressure value and the pressure indication of the empty box barometer or empty box barometer, hPa;
t——temperature value at the high temperature point, C;
12temperature value at the low temperature point, ℃.
5.3.6 Indication verification
JJG272-—2007
5.3.6.1 Only the empty box barometer and empty box barometer that have been verified by temperature coefficient can be verified by indication. Before the indication verification, the temperature of the empty box barometer and empty box barometer must be balanced with the room temperature. 5.3.6.2 The temperature coefficient correction value is obtained by multiplying the auxiliary temperature indication value of the empty box barometer by the temperature coefficient of the table (the auxiliary temperature indication value is replaced by the standard temperature value in the indication verification). 5.3.6.3 During the indication verification, the indication of the empty box barometer must be adjusted to a position where the value corrected by the temperature coefficient correction value is consistent with the standard value of the air pressure (after the indication correction) 5.3.6.4 The starting point and end point of each verification trip must be the upper and lower limits of the measurement range of the empty box barometer and empty box barometer (the empty box barometer can be set by itself according to the use range for subsequent verification and inspection during use). 5.3.6.5 The indication value verification point of the empty box barometer is 1010hPa, which is a mandatory inspection point. The interval of the verification points is 20hPa or 30hPa. During the subsequent verification and in-use inspection, the interval of the verification points can be enlarged to 50hPa, and there are no less than 5 verification points in the whole verification process.
5.3.6.6 The indication value verification points of the empty box barometer are: 1050hPa, 1030hPa, 1010hPa, 990hPa, 960hPa; the indication value verification points of the empty box barometer with a measurement range of (870-960)hPa are 960hPa, 940hPa, 920hPa, 900hPa, 870hPa; the verification points of the subsequent verification and in-use inspection can be reduced to the middle point (1010hPa or 920hPa) and the upper and lower limits of the measurement range. The indication verification method of the empty box barometer used in areas where the air pressure is lower than 960hPa all year round can adopt the normal pressure local verification method (see Appendix B). 5.3.6.7 The indication verification point should be at the point of 10hPa. When adjusting the standard air pressure value of each verification point, its deviation shall not exceed ±1.0hPa.
5.3.6.8 The indication verification of the empty box barometer and the empty box barometer includes one pressure increase stroke and one pressure reduction stroke. 5.3.6.9 The rate of pressure increase or pressure reduction adjustment during the indication verification process shall not exceed 5hPa/min. 5.3.6.10 Place the empty box barometer or empty box barometer in the indication verification box, and change the pressure from high pressure to low pressure, and then from low pressure to high pressure (the sequence is reversible). It must be continuous without pause in the middle, and keep the trend unchanged. 5.3.6, 11 When changing the direction of the calibration stroke at the high and low pressure endpoints of the calibration, the original pressure trend should be maintained to continue to increase or decrease to a pressure value exceeding the calibration point by about (23) hPa, and then the pressure should be changed in the opposite direction to adjust to this calibration point. 5.3.6.12 The stabilization time for each calibration point is: not less than 5 minutes for a barometer, not less than 10 minutes for a diary barometer, and not less than 20 minutes for a weekly barometer. 5.3.6.13 After stabilization, read the indicated value of the air pressure standard and the temperature value of the standard thermometer, accurate to 0.1 hPa and 0.1°C respectively. Then read the air pressure indication of the empty box barometer or empty box barometer, and estimate it to 0.1 hPa. After the empty box barometer has completed the indication calibration, read the pressure value of the self-recording line on the self-recording paper during the stabilization period of each calibration point.
5.3.7 Data processing of indication verification
5.3.7.1 The format of the empty box air pressure indication verification record sheet is shown in Appendix C, and the format of the empty box barometer indication verification record sheet is shown in Appendix D.
5.3.7.2 The average value of the pressure difference Ap at each verification point of the empty box barometer is calculated using formula (2): 5
JJG272-2007
Ap=[Bart-(px +K,t)]+[p称-(p*+K,t\)]2
Wherein: standard——
standard value of the pressure standard instrument at the pressure calibration point for the pressure increasing stroke (after indication correction), hPa; Pstandard
standard value of the pressure standard instrument at the pressure calibration point for the pressure decreasing stroke (after indication correction), hPa; air pressure indication of the empty box barometer at the pressure calibration point for the pressure increasing stroke, hPa; P装
p袋——air pressure indication of the empty box barometer at the pressure calibration point for the pressure decreasing stroke, hPa; K.
temperature coefficient, hPa/℃;
t——temperature value of the standard temperature at the pressure calibration point for the pressure increasing stroke, ℃; t\——lake value of the standard thermometer for the pressure calibration point for the pressure decreasing stroke ℃. (2)
5.3.7.3 The average value of the pressure difference of each calibration point of the empty box barometer shall be calculated according to the reference 2, but no correction is required for the temperature coefficient 50
correction value.
5.3.7.4 The average value of the pressure difference of each calibration point (the median point of the pressure range) of the empty box barometer shall be the final result of the indication at 0.0hPa. The average value of the value minus 1/Pa point (920hPa or constant) is used as the correction value of the indication in the pen position. 5.3.8 Verification of supplementary correction value 5.3.8.1 After the air value verification, the empty box barometer can be verified for supplementary correction value after being placed in natural conditions for 24 hours. 5.3.8.2 The method of verifying the correction value is to place the empty box barometer and the standard in the pressure laboratory and compare them under the same atmospheric pressure and room temperature. The pressure sensing parts of the empty box barometer and the pressure standard should be at the same position. 1. Condition
On the horizontal surface.
5.3.8.3 Read
0.1hPa, temperature value
0.1hPa.
The gas value of the standard instrument
The temperature value of the standard temperature
, the air pressure reading is accurate to
The number is accurate to 0.1%. Then read the air pressure indication reading of the empty box barometer. The reading is estimated to
. All comparison readings are times, and the time interval between each reading is not less than 1h. 5.3.8.4 Empty box gas
5.3.9 Data processing for verification of supplementary correction values 5.3.9.1 The record form for verification of supplementary correction values is shown in Appendix E. After correction, the pressure value of the empty box
barometer is obtained.
5.3.9.3 Subtract the standard air pressure value (after indication correction) from the air pressure value of the empty box to obtain the difference of 5 times. 5.3.9.4 Calculate the average value of the 5 differences (accurate to MTRO, which is the supplementary correction value of the empty box barometer. 5.4 Processing of verification results
According to the requirements of this regulation, the empty box barometer and empty box barometer that have passed the verification shall be issued with a verification certificate; those that have failed the verification shall be issued with a verification result notice, and the unqualified items and contents shall be indicated. 5.5 Verification cycle
The verification cycle of the empty box barometer and empty box barometer shall be determined according to the environmental conditions and frequency of use. Degree determined, empty box barometer generally does not exceed 1 year, empty box barometer generally does not exceed 3 years, 6
Appendix A
Indication value/hPa
Verifier
JJG272-—2007
Barometer, barometer temperature coefficient verification record form format Pressure standard
Correction value/hPa
Pressure value hp
Standard thermometer
Temperature value/℃
Instrument under test
Pressure indication/hPa
Pressure difference/hPa
Temperature coefficient/hPa
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METROLOGY
Appendix B
JJG272—2007
Normal pressure local calibration method for DYJ1 type empty box barometer B.1 This method is only applicable to DYJ1 type empty box barometers used in plateau areas (or areas where the annual air pressure range is lower than 960hPa).
B.2 The sensitivity of DYJ1 type empty box barometer has the characteristic of gradually increasing as the air pressure decreases. This method is established by utilizing this characteristic.
B.3 Key points of this method
B.3, 1 The average air pressure value (the nearest 10hPa value) at the location of the calibration agency is used as the midpoint value of the barometer pen position. The 90hPa range where this point is located is the normal pressure range. B.3.2 The range of 90hPa contained in the midpoint value of the average air pressure value of the place where the barometer is used is called the local range.
B.3.3 The normal pressure local range calibration method of the barometer is to control the sensitivity of the instrument when calibrating the barometer at a place within the normal pressure range, so that the barometer can be calibrated and qualified not only at the normal pressure range, but also at the local range where the barometer is used.
B.4 Specific contents of this method
B.4.1 Determine the difference between the total variable of the empty box barometer in the normal pressure range and the total variable of the standard instrumentB.4.2 Calculate the total variable control amount u from the normal pressure range to the localized range according to the following formula: ±= (pp) π ± 0.37 (hPa)
Where: P—
The midpoint pressure value of the normal pressure range, hPa;
p2——The midpoint pressure value of the localized range, hPa; π——The sensitivity coefficient of the DYJ1 type empty box barometer, in the range of (850~1050) hPa π=0.02, in the range of (600~850) hPa π=0.01; 0.37——Constant, take a positive sign when 2-≥0, and take a negative sign when P2-<0. The ratio is calculated accurately to 0.1 hPa.
Or, the value can be found in Table B.1.
Table B.1μ value calculation table
Air pressure range
1050-850
850-600
Based on the value, and looking up Table B.2, we can get the adjustment value △Z of the short arm of the lever system of the DYJ1 type empty box barometer (when B.4.3
is a negative value, △ is the increase of the short arm; when it is a positive value, △ is the shortening of the short arm). 82 The method for verifying the correction value is to place the empty barometer and the standard in the pressure laboratory and compare them under the same atmospheric pressure and room temperature. The pressure sensing parts of the empty barometer and the barometer should be located on the same horizontal plane under the same conditions. 5.3.8.3 Read the value of 0.1 hPa and the temperature value of 0.1 hPa. The air value of the standard instrument is the temperature value of the standard temperature, and the pressure reading is accurate to 0.1%. Then read the pressure indication reading of the empty barometer and estimate the reading to 0.1%. The total comparison reading is times, and the time interval between each reading is not less than 1 hour. 5.3.8.4 Data processing for verification of air box gas
5.3.9 Supplementary correction value verification 5.3.9.1 The record form for verification of supplementary correction value is shown in Appendix E. After correction, the pressure value of the air box
barometer is obtained.
5.3.9.3 Subtract the standard pressure value (after indication correction) from the pressure value of the air box to obtain the difference of 5 times. 5.3.9.4 Calculate the average of the five differences (accurate to MTRO, which is the supplementary correction value of the empty box barometer. 5.4 Handling of verification results
According to the requirements of this regulation, a verification certificate shall be issued to the empty box barometer and empty box barometer that have passed the verification; a verification result notice shall be issued to those that have failed the verification, and the unqualified items and contents shall be indicated. 5.5 Verification cycle
The verification cycle of the empty box barometer and empty box barometer shall be determined according to the environmental conditions and frequency of use. Generally, the verification cycle of the empty box barometer shall not exceed 1 year, and the verification cycle of the empty box barometer shall not exceed 3 years. 6|| tt||Appendix A
Indication value/hPa
Verifier
JJG272-—2007
Barometer, barometer temperature coefficient verification record form Format of pressure standard instrument
Correction value/hPa
Pressure value hp
Standard thermometer
Temperature value/℃
Instrument under test
Pressure indication/hPa
Pressure difference/hPa
Temperature coefficient/hPa
PPUBLISHING HOUSE
METROLOGY
Appendix B
JJG272—2007
DYJ1 type empty box barometer normal pressure local calibration method B.1 This method is only applicable to DYJ1 type empty box barometers used in plateau areas (or areas where the annual air pressure range is lower than 960hPa).
B.2 The sensitivity of the DYJ1 type empty box barometer has the characteristic of gradually increasing as the air pressure decreases. This method is
B.3 Key points of this method established by using this characteristic
B.3, 1 The average air pressure value at the location of the calibration agency (the nearest 10hPa value) is used as the midpoint value of the barometer. The 90hPa range where this point is located is the normal pressure range. B.3.2 The range of 90hPa contained in the midpoint value with the average air pressure value of the location where the barometer is used is called the local pressure range.
B.3.3 Barometer Normal Pressure Local Calibration Method The method is to control the sensitivity of the instrument when calibrating the barometer at a location within the normal pressure range, so that the barometer can be calibrated and qualified not only at a location within the normal pressure range, but also at a location within the local range where the barometer is used.
B.4 Specific content of this method
B.4.1 Determine the difference between the total variable of the empty box barometer at the normal pressure range and the total variable of the standard instrument B.4.2 Calculate the total variable control amount u from the normal pressure range to the local range according to the following formula: ± = (pp) ±0.37 (hPa)
Where: P—
midpoint pressure value of normal pressure range, hPa;
p2——midpoint pressure value of localized range, hPa; A——sensitivity coefficient of DYJ1 type empty box barometer, A=0.02 in the range of (850～1050) hPa, A=0.01 in the range of (600～850) hPa; 0.37——constant, positive when 2-≥0, negative when P2-<0. The ratio is calculated accurately to 0.1 hPa.
Or, the value can be found in Table B.1.
Table B.1μ value calculation table
Air pressure range
1050-850
850-600
Based on the value, and looking up Table B.2, we can get the adjustment value △Z of the short arm of the lever system of the DYJ1 type empty box barometer (when B.4.3
is a negative value, △ is the increase of the short arm; when it is a positive value, △ is the shortening of the short arm). 82 The method for verifying the correction value is to place the empty barometer and the standard in the pressure laboratory and compare them under the same atmospheric pressure and room temperature. The pressure sensing parts of the empty barometer and the barometer should be located on the same horizontal plane under the same conditions. 5.3.8.3 Read the value of 0.1 hPa and the temperature value of 0.1 hPa. The air value of the standard instrument is the temperature value of the standard temperature, and the pressure reading is accurate to 0.1%. Then read the pressure indication reading of the empty barometer and estimate the reading to 0.1%. The total comparison reading is times, and the time interval between each reading is not less than 1 hour. 5.3.8.4 Data processing for verification of air box gas
5.3.9 Supplementary correction value verification 5.3.9.1 The record form for verification of supplementary correction value is shown in Appendix E. After correction, the pressure value of the air box
barometer is obtained.
5.3.9.3 Subtract the standard pressure value (after indication correction) from the pressure value of the air box to obtain the difference of 5 times. 5.3.9.4 Calculate the average of the five differences (accurate to MTRO, which is the supplementary correction value of the empty box barometer. 5.4 Handling of verification results
According to the requirements of this regulation, a verification certificate shall be issued to the empty box barometer and empty box barometer that have passed the verification; a verification result notice shall be issued to those that have failed the verification, and the unqualified items and contents shall be indicated. 5.5 Verification cycle
The verification cycle of the empty box barometer and empty box barometer shall be determined according to the environmental conditions and frequency of use. Generally, the verification cycle of the empty box barometer shall not exceed 1 year, and the verification cycle of the empty box barometer shall not exceed 3 years. 6|| tt||Appendix A
Indication value/hPa
Verifier
JJG272-—2007
Barometer, barometer temperature coefficient verification record form Format of pressure standard instrument
Correction value/hPa
Pressure value hp
Standard thermometer
Temperature value/℃
Instrument under test
Pressure indication/hPa
Pressure difference/hPa
Temperature coefficient/hPa
PPUBLISHING HOUSE
METROLOGY
Appendix B
JJG272—2007
DYJ1 type empty box barometer normal pressure local calibration method B.1 This method is only applicable to DYJ1 type empty box barometers used in plateau areas (or areas where the annual air pressure range is lower than 960hPa).
B.2 The sensitivity of the DYJ1 type empty box barometer has the characteristic of gradually increasing as the air pressure decreases. This method is
B.3 Key points of this method established by using this characteristic
B.3, 1 The average air pressure value at the location of the calibration agency (the nearest 10hPa value) is used as the midpoint value of the barometer. The 90hPa range where this point is located is the normal pressure range. B.3.2 The range of 90hPa contained in the midpoint value with the average air pressure value of the location where the barometer is used is called the local pressure range.
B.3.3 Barometer Normal Pressure Local Calibration Method The method is to control the sensitivity of the instrument when calibrating the barometer at a location within the normal pressure range, so that the barometer can be calibrated and qualified not only at a location within the normal pressure range, but also at a location within the local range where the barometer is used.
B.4 Specific content of this method
B.4.1 Determine the difference between the total variable of the empty box barometer at the normal pressure range and the total variable of the standard instrument B.4.2 Calculate the total variable control amount u from the normal pressure range to the local range according to the following formula: ± = (pp) ±0.37 (hPa)
Where: P—
midpoint pressure value of normal pressure range, hPa;
p2——midpoint pressure value of localized range, hPa; A——sensitivity coefficient of DYJ1 type empty box barometer, A=0.02 in the range of (850～1050) hPa, A=0.01 in the range of (600～850) hPa; 0.37——constant, positive when 2-≥0, negative when P2-<0. The ratio is calculated accurately to 0.1 hPa.
Or, the value can be found in Table B.1.
Table B.1μ value calculation table
Air pressure range
1050-850
850-600
Based on the value, and looking up Table B.2, we can get the adjustment value △Z of the short arm of the lever system of the DYJ1 type empty box barometer (when B.4.3
is a negative value, △ is the increase of the short arm; when it is a positive value, △ is the shortening of the short arm). 81μ value calculation table
Air pressure range
1050-850
850-600
Based on the value, and then looking up Table B.2, we can get the adjustment amount △Z of the short arm of the DYJ1 empty box barometer lever system (when B.4.3
is a negative value, △ is the increase of the short arm; when it is a positive value, △ is the shortening of the short arm). 81μ value calculation table
Air pressure range
1050-850
850-600
Based on the value, and then looking up Table B.2, we can get the adjustment amount △Z of the short arm of the DYJ1 empty box barometer lever system (when B.4.3
is a negative value, △ is the increase of the short arm; when it is a positive value, △ is the shortening of the short arm). 8
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