Some standard content:
National Metrology Verification Regulations of the People's Republic of China JJG667—1997
Liquid Positive Displacement Flow Meter
1997 — r1 —20 Issued
1998-06-01 Implementation
National Technical Supervision Bureau Issued
JG6671997
Liquid Positive Displacement Flow Meter
Verification Regulations
VRof Liquid Positive
Displacemenl Flow Meter
JJG 667--1997
Replace JJG232—1981
JJG 2351990
JJG 634—1990
This regulation was approved by the State Bureau of Technical Supervision on November 20, 1957, and came into force on October 1, 1998:
Responsible unit: Hequ Technical Supervision Bureau
Drafting unit: Henan Measurement and Testing Institute, China Institute of Metrology
Technical drafting list of this regulation and explanation of this regulation Drafting person:
Xiao Wenqing
Kong Qingli
Article drafting person:
Xing ShuliWww.bzxZ.net
Zhang Huisheng
Yang Mingyi
J.IG667—1997
(Henan Measurement and Testing Institute)
(China Institute of Metrology)
(Henan Measurement and Testing Institute)
(Hequ Measurement and Testing Institute (Henan Province Measurement and Testing Institute)
(Henan Province Measurement and Testing Institute)
(National Water Flow Metering Station, Erfeng Junxiao!) (Hangzhou Hangwu Industry Corporation Flow Metering Station) (Hubei Province Measurement and Testing Institute)
II. Technical requirements
II. Determination conditions
(I) Experimental calibration
(I) Online calibration
IV. Calibration items and calibration methods
() Random quality and appearance inspection
() Pressure resistance test
(III) Output loss reduction test
(IV) Basic error and weight test-
V. Calibration result processing and calibration period
Starting flow
Appendix 2 Minimum measured
Appendix 3 Calibration certificate back element
JJG: 667-1997
(6】
: 667—1997
Verification Procedure for Liquid Positive Displacement Flowmeters
This procedure is applicable to the verification of newly manufactured, old and repaired liquid positive displacement flowmeters and flow sensors: 1. Overview
1 A meter that uses a mechanical measuring element to separate (partition) the flowing liquid into individual volume portions or even the total rapid flow rate is called a positive displacement flowmeter (hereinafter referred to as a flowmeter). A flowmeter is used to measure the flow rate of full flow in a closed pipeline, mainly measuring the cumulative flow rate (i.e. the total flow rate). 2 The flowmeter referred to in this procedure includes the following flowmeters and flow sensors: 1. a. Roots flow meter: a. Elliptical gear (also known as Roots) flow meter; C: Scraper flow meter: d. Rotor flow meter: E. Rotor flow meter: F. Plate flow meter: F. Tide rod flow meter: H. Double rotor flow meter; 1. Other types of flow meters and various types of flow sensors (hereinafter referred to as sensors): The indication devices of flow meters are divided into direct reading and transmission types. The point meter may be equipped with the following devices with one or more special functions: a. Correction (compensation) device; h. Zero device; f. Repeat indication device; g. Printing device; tt. Memory device; f. Conversion device; g. Preset device; tt. Price indication device. 4 The main arrangements of this regulation are listed in Tables 1 and 2, and other numbers may be related to the following: 2. Technical requirements 5. Random documents 5.1 The meter should have instructions for use.
5.2 The flowmeter to be subsequently tested shall have the previous calibration certificate: 1
Differential coefficient
J; 667—1997
Quantity represented
Sensor system
General physical principle of standard indication
Number of pulses measured by the transmitter display
Liquid flowmeter
Value of the unit of the indicator device
Polymer Hourly flow
wavelength
liquid volume value
measured
price data error of each inspection point
minimum volume segment
liquid expansion coefficient
basic reading difference of flowmeter
loss of quantity
predicted error
liquid, scale index system
liquid at standard instrument
table 2 Corner mark
Popularity
Verification points, 3
Number of verifications, 3
Meter being tested
Most popular
I.-'m It-:
n or 1
Smallest
Standard condition
Standard
6 External appearance
JJG 6h7--1997
6.1 The surface of the newly manufactured flow meter should have good surface treatment, without visible defects such as thorns, scratches, cracks, rust or stains
6.2 All markings should be obvious and clear
6.3 The fluid channel of the flow meter should be clean and the inner surface should be smooth. 6.4 The indicating device of the flow meter (including its auxiliary devices) shall also meet the following requirements: 6.4.1 The back of the indicating dial shall have no defects such as stone pools, group patterns, obvious defects, etc. that may affect the reading and appearance.
6.4.2 For an indicating device with a digital wheel, the numbers should be clear and in the correct position. The wheel should run normally without any downward movement.
6.4.3 For an indicating device with a minimum output, the numbers and symbols should be clear, straight and neat. 6.4.4 The data transmission of auxiliary devices (such as finger, pressure gauge, alarm, memory, preset and full display, etc.) using a digital wheel should be correctly set:
.4.5 The zeroing mechanism of the indication value should be able to return to zero correctly. The zeroing operation should not change the display of the device (except for the disappearance of other displayed results and replacement of four results).
7 Marking
.1 The flow meter housing should be marked with a flow meter. .2 The meter shall have a nameplate. The shell or nameplate shall indicate the following: Manufacturer name and (most) international:
h. Flow meter name and model:
c: Meter equipment manufacturing license mark;
d. Nominal diameter:
e. Flow meter;
1. Explosion grade;
g. Nominal force (or force range);
1: Explosion grade mark and explosion certificate number (this item is only applicable to explosion-proof flow meters), factory number, etc.
7.3 The flow meter shall have a printed mechanism and information protection component that can be adjusted to affect its accuracy. 7.4 The flow meter shall have a fire-proof auxiliary device The following markings shall be placed on the auxiliary device: Manufacturer (or) factory mark: Name and model: , Export! Total three + , the matching instrument number (applicable to the dedicated device): 8. The accuracy level and the error of the flowmeter shall comply with the provisions of Table 3: 8.2 Unless otherwise specified, the accuracy level of the flowmeter shall only be increased. 8.3 If the flowmeter has an indicator device: The basic design of each indicator device shall not exceed the regulations in Table 33. Accuracy level and basic error limit ||Brackets and other blanks are not included in the coupons.
JJG667—1997
8.4 If the flowmeter is equipped with a peak stop correction device, the error after repair shall not exceed the minimum specified in Table 3. 2.5
8.5 The indication of the flow indicator is opposite to the flow indication of the flowmeter. The error of the last digit of the flow indication is allowed to be equal to 1.
9 Repeatability of the pressure point of the flowmeter shall not exceed 1.0% of the basic error limit of the flowmeter.
For flowmeters with requirements for the starting flow and the minimum measured value, the relevant requirements are shown in Appendix 1 and Appendix 2 respectively. Pressure-resistant channel seat
Flowmeter in 1.There should be no leakage and revealed pressure loss under 5 times the nominal pressure. The pressure loss of the flow meter should be less than that specified in the product manual. 3. Verification conditions: [1. Laboratory verification] 13. Flow standard device for verification 13.1 The flow standard device (hereinafter referred to as the device) and its auxiliary measuring instruments should have a valid verification certificate: 13.2 The error of the device should generally not exceed 1/3 of the basic error limit of the flow meter, and at least not exceed 1/2 of the basic error limit of the flow meter.
13.3 Capacity of the device
13.3.1 The flow range of the device shall also cover the flow range of the flow meter. 13.3.2 During the verification, the amount of liquid passing through the flow meter shall be as follows: a. For flow meters without pulse output, the verification time shall not be less than 3: for flow meters with an accuracy of 0.1-0.3, the amount of liquid passing through shall not be less than 1500 times the minimum scale value; for flow meters with an accuracy of 0.5, the amount of liquid passing through shall not be less than 100 times the minimum scale value; for flow meters with an accuracy of less than 1.0%, the amount of liquid passing through shall not be less than 500 times the minimum scale value; b. For flow meters with pulse output, the relative error of the pulse count during the verification shall not exceed 1/3 of the repeatability of the meter.
13.4 For flow meters with an accuracy of more than 1.0%, the liquid temperature at the flow meter and the standard shall be measured periodically. For flowmeters with good flow efficiency, the liquid pressure at the outlet (or inlet) should be measured. A pressure gauge can be installed near the flowmeter. When the liquid at the standard is positively charged to ten times the atmospheric pressure, the pressure at the standard can be measured. When there is a full pressure loss, the pressure at the inlet and outlet of the flowmeter should be measured. Measuring differential pressure: The axis of the pressure hole should be perpendicular to the axis of the measuring tube, the hole diameter is 6~10mm, and the edge of the hole should be burred and protruded: the upper limit of the pressure gauge is 1.5-2 times the maximum pressure at the flow meter (the maximum differential pressure when measuring pressure loss), and the basic error of the pressure gauge generally does not exceed ±1%. 13.6 The change of the instantaneous flow indication resistance of the device does not exceed +2.5%: 13. When calibrating the flow meter, when the vapor pressure of the test liquid is higher than the atmospheric pressure, the device should be closed to ensure that the test liquid is isolated from the atmosphere.
14 Test liquid
1 4.1 The calibration liquid should be clear, without particles, fibers, etc. If necessary, a filter can be installed in the upstream pipe of the flow meter.
14.2 The liquid should fill the test pipe, and there should be no air in the liquid. If necessary, a degasser should be installed in front of the inlet of the upstream pipe of the flow meter.
14.3 Liquid viscosity resistance
14.3,1 The viscosity of the liquid should be consistent with the viscosity of the actual measurement liquid of the flow meter as much as possible. When other liquids are used, the error caused by the difference in viscosity between the calibration liquid and the actual measurement liquid to the flow meter generally does not exceed 13 of the basic error limit of the flow meter. | |tt||14.3.2 If the viscosity of the working liquid of the flowmeter is not greater than 2mP8, the accuracy is not higher than 0.5 level, and the working liquid viscosity is not greater than 5na·5, it is allowed to use water for calibration without causing corrosion and damage to the flowmeter. 14.3.3 If the viscosity of the working body of the flowmeter is 5--50mPa'8, the viscosity of the calibration liquid should not be less than 5mPa-s, and the difference with the viscosity of the actual measured liquid of the flowmeter should generally not be greater than 9mPa-d14.3.4 If the viscosity of the working liquid of the flowmeter is 55Pa, the viscosity of the calibration liquid is only required to be not less than 50 mPa's.
14.3.5 If a flowmeter is used to measure a variety of liquids at different distances, it should be configured with liquids of minimum, (or close to minimum) and maximum (or close to maximum) viscosity respectively, under the conditions of Item 17.4.1. 14.4 When the calibration liquid cannot meet the requirements of Item 14.3, the viscosity can be corrected according to the viscosity correction calculation formula (or correction curve, correction data table) provided in the product manual of the flowmeter. 14.5 The pressure at any point in the test system and flowmeter of the calibration liquid should be higher than its chain and steam pressure. For liquids that are easy to vaporize, there should be a certain back pressure in the flowmeter. The recommended back pressure is twice the pressure of the flowmeter at the maximum flow rate, plus 1.25 times the saturated natural steam pressure of the calibration roller at the highest calibration temperature. 15.1 Pressure resistance test device: its rated working pressure shall not be less than 1.5-2 times of the nominal pressure of the flowmeter, and the error of the indication of the flowmeter shall not exceed 12.5%.
15.2 Environmental monitoring instrument
JJG667·1997
a, temperature: its permanent value difference shall not exceed +0.5:h. Mud density: if necessary, its indication error shall not exceed 5.0;. Barometer: if necessary, its indication error shall not exceed 1.1,15.3 When it is necessary to measure the density of the water, a density meter with corresponding accuracy shall be used: a. For flowmeters with an accuracy higher than 0.5 level, a standard density meter of the same level shall be used; b. Except for the case of Article 15.3a, a conventional density meter may be used, and the graduation value of the density meter shall be less than 0.1%. 15.4 When it is necessary to measure the viscosity of liquid, a viscometer with corresponding accuracy should be provided. The measurement error should generally not exceed 5% of the viscosity of the liquid being measured.
16 Environment
When the instrument is tested, the following environmental conditions should be met: 16,! Experimental environment
a: Atmospheric temperature: 15-35℃, the maximum allowable change is 1% change per 10min; b, relative humidity: (45·7S)%; c, air pressure 86-108kPa
: The ambient temperature should not exceed 10℃, and the instrument performance should not be affected by this. 162 During calibration, the influence of mechanical dynamics on the flowmeter should be so small that it can be ignored. 16.3 For near-field meters that require power supply, the power supply conditions specified in the flowmeter instruction manual should be met. 16.1 During calibration, the influence of external magnetic fields on the flowmeter, except for the magnetic field, should be so small that it can be ignored. [II) Online calibration
17 The device conditions in Article 13 and the environmental conditions in Article 1 should be met: During calibration, the two devices of the level calibration should be connected to the output (or input) pipe of the flowmeter, and there should be no bypass flow (or flow) between the meter and the device! Liquid,
Fourth verification items and verification methods
(I) Random documents and appearance inspection
18 Check random documents, the results should meet the requirements of Article 5: 19 Use the test method to check the appearance of the flow meter, the results should meet the requirements of Articles 6 and 7, (II) Pressure resistance test
20 Fill the flow meter cavity and channel with the test filter, and then gradually increase the pressure to 1.5 nominal pressure for 5m, the flow meter should not be damaged and seep: Generally, the liquid that is close to the measured body material and does not cause corrosion and damage to the instrument is used as the test body.
21 Newly manufactured and the shell or pressure seal, after the static seat, the anti-sense meter should be subjected to the pre-pressure strength test. The flow meter that is subsequently verified may be exempted from this test according to the situation. 22 Online calibration - pressure drop test 23 ± Strength test is allowed only for the complete body of the flowmeter and the sealed parts: (i) Pressure loss test
J667-1997
24 Pressure loss is the difference between the inlet and outlet of the flowmeter at the maximum flow rate 23 Pressure loss test can be carried out at the same time as basic error calibration. The positive pressure loss value shall not exceed the provisions of Article 12. (IV) Basic error and repeatability calibration
26 Determine the calibration method and calibration equipment: If it is a case calibration, it shall comply with the requirements of Articles 13 to 16; if it is an online calibration, it shall comply with the requirement of Article 17
27 Connect the auxiliary liquid of the flowmeter and its matching transformer to the flow standard, and replace other necessary measuring instruments. Make the flowmeter and its calibration peripheral system filled with liquid, and the seals must be leak-proof. 28 Generally, make the flowmeter run at 70%-1% of the maximum flow rate for at least 5 minutes (when this operating condition is not available, it is allowed to run for at least 1in) before basic error calibration can be carried out. 29 Calibration points
24.1 For flowmeters with accuracy level better than .5, the calibration points shall be no less than 5, evenly distributed, including the minimum flow rate and the maximum flow rate:
29.2 Except for the case of Article 2.1, the flowmeter shall have no less than 3 calibration points, evenly distributed, including the minimum flow rate and the maximum flow rate.
3 The difference in flow values at the calibration points shall not exceed 2.5%. 31 For flowmeters with preset devices, after the calibration points are installed, the preset calibration values shall be set according to whether the device is installed. 32 Calibration coefficient
32.1 At least 3 calibration points shall be performed for each calibration point.
32.2 The flow indicator device shall be calibrated once at each flow point. 33. During each calibration, read and record the flow meter indicator value, standard instrument value and other measuring instrument minimum value. 33.1 Flow meter indicator value, including: 3. Flow meter direct reading instrument value:
bh: flow meter remote transmission instrument minimum value;
c, multiple water indicator value;
d. Memory device start and end value;
e: Neck device value;
f Zero device return deviation value:
. Price and total price value of the price meter; h. Conversion and replacement value, etc.
3.1.2 The indication of the standard instrument
should be read and recorded according to the requirements of the device used. 3. When necessary, the indication of the standard instrument and environmental parameters should be read and recorded, including: a. The indication of liquid temperature, pressure drop, pressure loss, viscosity, density, etc. b. The minimum value of ambient temperature, humidity, atmospheric pressure, etc. 34. The actual volume of the standard instrument measured during the calibration is calculated according to the calibration points at each time: The actual value of the standard instrument fluid is as follows:
34.1 Volume tube method
Where:
The reading of the standard instrument: 667-17
.1 + 2.++. - 20).
·The average value of the liquid pressure at the standard flowmeter, Pa; D-the inner diameter of the standard volume tube, Mn;
-the standard quick-flow pipe, m
L,-the standard volume material projectile model, Fa:3-the seasonal expansion coefficient of the standard instrument ℃
-the average value of the liquid temperature at the standard instrument.
V = Vl1 f(t, 20).
34.3 The single-feed weighing container is a pound-effect structure) Mac
-the amount of liquid to be weighed: k product:
In the formula:-
the density of the liquid at the standard instrument, kg:
-the pollution correction coefficient:
Cr edri fa
Fto, -p
Calibration ambient atmospheric temperature, k:
The density of the calibration code, /m
Or if the brick code is not used, then
22,1 Standard table method
Wu: (mark the correction factor of the flow meter, the correction factor is determined according to the standard determination card. 35 Calculate the value of V to the actual flow value of the system under the calibration conditions of the flow meter Q = vil+ tt - )lfl -(pne]
In the test: Q, convert the liquid volume at the standard instrument to the cumulative flow value under the flow conditions: -—·Concentrated expansion coefficient:
-Concentrated contraction coefficient;
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