Some standard content:
National Metrology Verification Regulation of the People's Republic of China J.TG 942—1998 Ball Pneumatic Dead Weight Tester1998-11-16 Issued
Implementation on 1999-05-01
State Administration of Quality and Technical Supervision Issued
JJG 942-Verification Regulation for Ball P'neumatic Dead Weight Tester1998
J.IG942—1998
This small metrology verification regulation was approved by the State Administration of Quality and Technical Supervision on November 16, 1998, and came into effect on May 1, 1999.
Responsible unit:
National Pressure Gauge Technical Committee
Shandong Institute of Metrology
Drafting unit:
The technical text of this regulation shall be interpreted by the drafting unit. The main drafter of this regulation:
Liu Jiyi
Participating drafter:
Zhang Lejian
JJG942—199A
(Shandong Institute of Metrology)
[Shandong Institute of Metrology]
[Liaoning Quality and Metrology Inspection Institute
(Jiangsu Institute of Metrology and Testing Technology)
Technical requirements
Registration conditions
Verification date and verification method
V. Verification result processing and verification validity period
I.IG 942—1998
Appendix 1 Method for determining the relationship between positive and negative flow rate. Calculate the compliance of each city. Appendix 4: Air buoyancy correction coefficient for each main city (). Appendix 5: Calibration record of float K force meter. Format of internal calibration certificate. Appendix 6: Instructions for use. J.1 942-199x
Verification Procedure for Float Pressure Gauge
This is applicable to the initial determination of the float pressure gauge used in new manufacturing, production and repair. Overview
The float pressure gauge consists of a float and nozzle, a special flow regulator, a gas filter and a base.
Its process: The original ball is a round ball placed in a valve-shaped valve-shaped spray screen. The gravity of the ball, the filter and the filter acts on the top of the ball. The gas from the air source passes through the flow regulator and the filter to spray the ball. The spray force acts on the nozzle to make the ball float up. When the compressed gas is balanced with the weight of the float and the filter, the flow meter can be output. The floating pressure gauge can produce a stable and accurate high and low value. The floating pressure gauge can be divided into automatic adjustment type and medicine adjustment type according to the flow measurement section. The floating ball pressure gauge can be divided into single-volume type and multi-range type according to the use requirements: 3. Technical requirements 1. Appearance 1.1 The float pressure gauge and the float ball should be clean and smooth, and there should be no corrosion, scars, burrs and other defects that may affect the performance of the gauge. 12. The code and code frame should be accurately matched, not loose or too tight, and can maintain the same shape and size. The newly manufactured code and code frame should be in good condition, and the surface should be smooth, free of rust and other defects. Special and special frame should have quality adjustment cavity, quality adjustment nail should not be high mountain. Its appearance has: 1.3 The bottom rate of the float pressure gauge should be 1:1, and there should be a good level and level adjustment. 1.4 The float pressure gauge of the manual station should be equipped with a precision indication device. Its flow regulator should be flexible. 1. The float pressure gauge should have the following markings: The float pressure gauge should have the machine name, model, version number, measurement state, manufacturer name, year and month of manufacture, and manufacturing license. Mark and serial number, as well as rated gas source pressure. Special code, instrument number and force value: For many float pressure gauges, each corresponding special code should be marked to distinguish them. "Allowable basic temperature difference
The accuracy level of the float pressure gauge should be consistent with the allowable error in Table 1. The accuracy level is 10% of the working medium of the product. The upper limit of the measurement is 30%. The upper limit of the measurement is 10%. I. [G: 942—199N
Jinli production bay record limit
10%-·1008 time
actual measurement estimate
actual measurement value
measurement range is not within the time
welcome to the upper limit
measurement upper
float type nozzle Ningxin load and level mountain book Kangpi wasteland, difficult first float type design should not be people in 2: etc. float type out of people under 5
The floating tower is effective and the cumulative net ball makes the comfortable ball effective with the extreme eye error and the servant change theory should not exceed 2. The table of contents has the stimulation surface stimulation
accuracy level
5 to avoid the stability of the cloud
teaching limit error
evaluation has the stimulation surface rental
annual rate of change
0.01% of the annual
deep ball pressure square meter car full volume format within the French, the ball is flat for you! There should be no impact on the work of the meter. The flow rate change should not affect the input flow rate (dynamic regulation test). When the flow rate changes to the meter, the output pressure change is small, and the floating ball pressure meter should not be affected by the pressure change (dynamic throttling type). The three-dimensional ball pressure meter should not be affected by the pressure change of 0.025
7 (dynamic throttling type). When the gas source pressure changes within a certain range, the output of the float pressure meter will be twisted to the left. For the second-class float pressure meter, it should not be more than 0.02%.
Specialized Weak quality
special code quality collection related information:
etc. Chinese ball meter is -1:
etc. ball +
inspection completed equipment
JJG9421998
three inspection conditions
standard commitment: signed the ball meter, adopted a common method of production, the corresponding force meter: the second-class ball meter is a force meter, adopted the first-class standard working length or demonstration method, the accuracy of the meter and the other results are not yet achieved if-
day and a half: grade amount,
turn: grade m, red.
Meter application requirements: Graduation: 1-1:
Steam trap: Can be calibrated to the standard output value for suitable production: 10
Select environmental conditions
10) Ambient temperature: The calibration value of first-class float pressure gauge is (20-1)C: The calibration value of second-class float pressure gauge is +2r.
.? Humidity: different %
should affect the setting vibration and airflow
floating city power is not necessarily the same as the test system under the different 2-way test out and two as a sense
the ball to the sub-total test with 1 as the quality type for clean, dry media, no edge, no quality of the air, four
signing items
test items and test methods
check items see Table 3 in the table "
" means it is difficult to determine, "" means it can be installed, "" means it is installed in the top of Table 3
test items F ||tt| |Verticality of the nozzle
The vertical ... 15. Ball effective area
is the effective area of the float. The rated air source pressure is used. For the float type dynamometer with dynamic throttling, the pressure flow relationship should be given in the first calibration certificate: for new manufacturing and repaired, the pressure flow relationship should be measured first. The measurement method is shown in Appendix 1. After signing, the ball effective area is determined according to the new pressure flow relationship. 15.1. Use the active type dynamometer certificate.1 Use piston pressure gauge (or active pressure vacuum gauge 1) as standard instrument, and calibrate the float pressure gauge. As shown in the figure, connect the tested float pressure gauge and the standard pressure gauge, and adjust the stand-alone position of the two gauges: When the working medium of the standard pressure gauge is liquid, a venting separator should be connected between the tested float pressure gauge and the standard pressure gauge.
Figure 1 shows the schematic diagram of the effective measurement of the float pressure gauge.
1 Tested float pressure gauge: 2 Standard pressure gauge 15.1.2 Calibration points: Select at least 5 points including 10% and 100% of the upper limit as calibration points (the lower limit of the measuring ball pressure gauge is higher than 10% of the upper limit, then take the lower limit point as the first calibration point). When the working medium of the standard pressure gauge is gas, set the starting point: When the working medium of the standard pressure gauge is liquid, the first calibration point can be set. 15.1.3 Add the special code of the specified pressure to the inspected pressure gauge and the standard pressure gauge, adjust the temporary gas source pressure to the rated value. For the manually adjusted float pressure gauge, the pressure source pressure should also be adjusted according to the given or newly measured pressure flow rate. When the standard pressure gauge is in the working position, add a small code to the standard pressure gauge until the standard pressure gauge remains unchanged. Record the energy code and small shear mass on the standard pressure gauge and the float pressure gauge. 15.1.5 The effective area of the float is calculated according to formula (1): A =n lam,
Where: - float type pressure gauge, the single value of the effective area of the float at the first calibration point, the effective area of the piston of the standard pressure gauge: A
, - the first calibration point, the special magnetic code of the float type pressure gauge, kg, - the first calibration point, the small code added to the float type pressure gauge, m, - the first calibration point, the special code added to the standard pressure gauge, kx - the first calibration point, the small code added to the standard pressure gauge, k. A
15.2 Direct reading pressure gauge () *
Use a direct reading force gauge as a standard to calibrate the float pressure gauge, as shown in Figure 2. Connect the float pressure gauge and the standard pressure gauge, and adjust the vertical position of the two pressure gauges. Figure 2: Schematic diagram of effective area measurement. 15.2.2 Calibration points: Select at least 5 points including 1% and 10% of the upper limit of measurement as calibration points (if the lower limit of the float or pressure gauge is smaller than the upper limit, use the upper limit of the float or pressure gauge). The measurement limit point is used as the first verification point without setting the starting half-balance point.
15.2.3, add the special code that can produce the specified pressure to the float pressure gauge, adjust the gas source pressure to the full rated value (for the float pressure gauge of dynamic throttling monitoring, the input flow should also be adjusted according to the newly measured pressure-flow relationship given in the calibration certificate)
Wait for the positive and small delays to stabilize and read the indication value of the standard pressure gauge 15.2.4 The single value of the effective ball pressure is calculated according to formula (2: The new point is used, formula rw, blood m, suppress the heart, and the female is used as a comparison point. The effective carbon is good and the small deficiency can be obtained for calculation.
JJC 942—-1998
3--Inspect the effectiveness of the air flotation system, see Appendix 3 (when the air density is 1.2kg/m3: 9-Wu:
0.999 553:
--Inspect the gravity acceleration at the inspection point, u";
---The standard pressure gauge at the first stock fixed point is evaluated, Pl15.3 The float is effective and the product is carried out in a positive and negative cycle with the fixed point of the connection standard. When there is an initial balance point, adjust the starting half point at the middle limit of the sequence measurement, and then perform the verification when the scale is determined. 15.4 The float is half-averaged in the product, and the product is calculated according to (1) or (2) as a single position according to formula (3): zA
Wu Bao.| |tt||The effective area of the float is averaged, m:
The float has a single value of the effective area,
15.5 The identification of the float effective area and the error of the float effective area shall meet the requirements of the requirements. 15.5.1 The standard deviation of the float effective area: 5a
The standard deviation of the effective area of the float, tr, the difference between the single value of the float effective area and the average value, 15.5.2 The limit error of the float identification: 3$A
X 100%
The limit error of the deep ball area,%.
15.5.3The rate of change of the effective area of the sequence ball
4x10x100%
2-The annual rate of change of the effective area of the float ball,%;
The effective area of the float ball is drawn in the above test.
1GThe stability of the float ball operation
The stability of the float speed operation is observed in the 5 tests of the industry, and the full range of the bending process, the formula pressure To prove that the float does not affect the performance of the meter, the dynamic model
17 input changes are affected by the cloud
JJG9421998wwW.bzxz.Net
For the flow meter that must be adjusted, the input method changes the color of the float in the calibration. The upper limit of the measurement base of the float type positive meter, the measurement equation of the bed six meter flow: make it change 05 points, mark as small, the positive force on the meter should meet the rules of the platform and not appear. 18 gas said positive force response
for the dynamic adjustment card flow volume still float dynamometer, the gas head is the force change closely with the effective accumulation of the pre-floating ball, in the upper limit of the ball type dynamometer, the test gas is not the force source force change range of 1, the lower limit value, the standard pressure gauge fast response mountain force change year family medicine combined small current process normal regulations: 19 can be based on the code
[9? Pressure code "package live float! Foundation leakage frame:, hemp connects the effective area of the ball, so that the three places of some force Acceleration, the plate room is a force test sequence, which includes the following plans: pa
the quality of the folding of the float (including the float and the foundation frame), the measured bed force value, Pa
1 the calibration reference method of the special mother's calibration plan is selected and its quality must meet the requirements of the public standard book No. 1319. Calibration of multiple floating dynamometers
For multiple floating dynamometers, each product and gear shall be calibrated according to the 1319th chapter of this procedure. V. Processing of calibration results and calibration cycle
21. Processing of calibration results
After the registration of the qualified ball square meter, a calibration certificate shall be issued: if it is unqualified, the calibration conclusion shall be corrected and the road shall be noted.
22 Calibration rules
Calibration period: 1 year
Appendix 1
JJG942-1998
Method for measuring pressure-flow relationship
For the float type pressure gauge with effective adjustment, after manufacturing and repair, its pressure-flow relationship should be determined. After the pressure-flow relationship is determined, the effective area of the float is calibrated according to the new pressure-flow relationship. Measuring point: Select the calibration point of the ineffective area of the calibrated float and the lower limit point of the float type submeter as the measuring point. 2 Determination method
If a standard pressure gauge cannot cover all the measuring points, the remaining measuring points can be measured with another standard pressure gauge of the same grade:
2.1 Using a standard pressure gauge as a standard When measuring the normal force relationship, as shown in Figure 1, connect the float pressure gauge and the standard force gauge, adjust the straight position of the two force gauges, respectively, at the standard pressure and float pressure gauge, add the special pressure code, and then adjust the input pressure to be tested, so that the pressure gauge and the float pressure gauge are in a balanced state. At this time, the indicated flow value Q of the flow gauge is the input flow of the first measuring point.
During the test: 4--effective area of the float (the new pressure gauge is the theoretical value; the standard pressure gauge is the last initial value);
is the effective area of the standard pressure gauge, n; A
:--the maximum pressure value corresponding to the first fixed point, Pa; m---the mass of the special base weight added to the float pressure gauge at the first measuring point, kg;
--gravity acceleration at the calibration site, mg;--air buoyancy correction coefficient at the calibration site. 2.2. When using a direct reading type dynamometer as a standard instrument to measure the pressure-flow relationship, as shown in Figure 2, connect the float type dynamometer and the standard pressure gauge, adjust the vertical position of the two pressure gauges, add a special code to the float type pressure gauge to produce the specified pressure, and adjust the input flow rate of the pressure to be tested to make the indicated pressure of the standard dynamometer equal to the nominal pressure at the measuring point. At this time, the indicated flow value of the flow meter is the value of the first measuring point. h
To measure the pressure-flow relationship, each measuring point is passed once, and the measured flow value is recorded in the input flow column of the test result:
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