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Verification Regulation of Coriolis Mass Flow Meters of the People's Republic of China JJG1038—2008
Coriolis Mass Flow Meters
2008 - 03 - 25 Issued
2008—06-25 Implementation
Issued by the General Administration of Quality Supervision, Inspection and Quarantine JJG1038—2008
Verification Regulation of
Goriolis Mass Flow Meters
JJG 1038:2008
Replaces JG897-1995
Coriolis quality controlbzxZ.net
Flowmeter part
This verification procedure was approved by the General Administration of Quality Supervision, Inspection and Quarantine on March 25, 2008, and took effect on June 25, 2008.
Responsible unit: National Technical Committee on Flow and Capacity Metrology Main drafting unit: Shanxi Xinzhou Quality and Technical Supervision Inspection and Testing Institute, China Institute of Metrology Participating drafting units: Liaoning Institute of Metrology Huisu Institute of Metrology and Testing Technology
Dalian Zhonglong Instrument Co., Ltd.
Shanghai Chengbo Automation Equipment Co., Ltd.
Taiyuan Aviation Instrument Co., Ltd. Flow Meter Factory Emerson Process Control Co., Ltd.
This regulation is entrusted to the National Technical Committee on Flow and Capacity Metrology to interpret this regulation Main drafters
JJG1038-2008
Duan Huiming (China Institute of Metrology) Shao Xi (Shanxi Xinzhou Quality and Technical Supervision Inspection and Testing Institute) Participating drafters:
Chen Mei (Liaoning Institute of Metrology) Huang Zhaohui (Jiangsu Institute of Metrology and Testing Technology) Sun Huachun (Lianzhonglong Instrument Co., Ltd.) Cheng Xianxi (Shanghai Chengbo Automation Equipment Co., Ltd. ) Ren Dongshun (Taiyuan Aviation Instrument Co., Ltd. Flow Instrument Factory Zhang Leichun (Emerson Process Control Co., Ltd.) 2
Scope·
References·
Terms and definitions·
4.1 Working principle,
4.2 Composition
Purpose·
4.4 Output signal--
5 Metrological performance requirements
Level of accuracy
Repeatability
6 General technical requirements Technical requirements
Random documents
Logo and nameplate·
Appearance·
Protective function
Sealing
7 Control of measuring instruments·
Verification conditions
Verification items and verification methods
7.3 Processing of verification results
7.4 Verification cycle··
Appendix A
Appendix B
Outline of type evaluation
JJG 1038--2008
Verification certificate/verification result notice (inside page) format (1)
(2)
(3)
(4)
(7)
1 Scope
JJG1038--2008
Coriolis mass flowmeter verification procedure
This procedure applies to the type evaluation, initial inspection, continued inspection and in-use inspection of Coriolis mass flowmeter (hereinafter referred to as flowmeter).
References
The following standards and specifications contain provisions that constitute the provisions of this procedure through reference. JJF1091-2002 Technical specification for characteristic evaluation of measuring instruments JJF 1004-2004 Flow measurement terms and definitions GB17820--J999
Natural gas
GB502512003 Gas transmission pipeline design rules
GB/T13609-1999 Natural gas sampling guide GI3/T13610-2003 Composition analysis of natural gas by phase chromatography GB/T17747.2-1999 Calculation of natural gas reduction factor: Part 2: Calculation by composition GB3836.1:2000 Electrical equipment for explosive gas atmospheres Part 1: General requirements Electrical equipment for explosive gas atmospheres Part 2: Flameproof type "\GB 3836. 2—2000
(B3836.32000 Electrical apparatus for explosive gas atmospheres Part 3: Increased safety type "e\ When using this regulation, please pay attention to the use of the current valid versions of the above-mentioned referenced documents. 3 Terms and definitions
In addition to the terms and definitions quoted in JII1094-2002 and JF1004-2004, the regulations also use the following terms and definitions.
3.1 Flow factor f (meter factor) is the factor used to perform actual flow inspection on the flowmeter and correct the mass flow indication of the flowmeter according to the inspection results: H value is the ratio of the mass flow of the standard instrument to the maximum mass flow indication of the flowmeter - generally represented by the symbol F, 3.2 Zero point offset (zero olfset)
Before zero point adjustment, when the medium in the flowmeter is stationary, the instantaneous mass flow indication of the flowmeter: can be reduced or eliminated by zero point adjustment.
3.3 Zero stability After zero adjustment, when the medium in the flow meter is stationary, the instantaneous mass flow rate of the flow meter is indicated by the absolute value of the instantaneous flow rate.
3.4 K coefficient (pluses per unit) The number of pulses emitted by the flow meter when a unit mass of fluid passes through the flow meter. 1
4 Overview
4. Working principle
JJG: 1038—2008
The Coriolis force generated by the fluid flowing in the perturbation tube is used to measure the Coriolis force directly or indirectly to obtain the fluid mass flow rate. There are many types of vibrating tubes. Figure 1 shows the working principle of L-type vibration. Medium flow
Coriolis force 2
Medium flow
*Coriolis force
Figure! The working principle diagram of U-type vibrating tube
4.2 Composition
The flowmeter consists of sensor and transmitter, in which the sensor is mainly composed of vibration tube, driving components, etc., and the transmitter is mainly composed of measuring base and output unit, etc. 4.3 Purpose
The flowmeter is mainly used to measure the mass flow rate of fluid. A.1 Output signal
The output signal of the flowmeter includes pulse, DC current, digital signal, etc. 5 Measurement performance requirements
5.1 Accuracy grade
Table 1 shows the recommended flow meter accuracy grade and the corresponding allowable error. If an accuracy grade other than that listed in Table 1 is used: its allowable error conforms to the corresponding principle in Table 1, Table
Accuracy grade
Allowable error ()
5.2 Repeatability
Flow meter accuracy grade and the corresponding allowable error 0.2
The repeatability of flow meter shall not exceed 1/2 of the absolute value of the allowable error specified for the accuracy grade. 6
General technical requirements
6.1 Random documents
6.1.1 The flow meter shall be accompanied by an instruction manual. The instruction manual shall give the name, model, measuring medium, working pressure range, working temperature range, nominal diameter, flow range, zero point stability, accuracy level, power supply voltage, flow sensor material, manufacturing unit, manufacturing measuring instrument license mark and code, explosion-proof level and explosion-proof certificate number (for flammable and explosive occasions), protection level, installation conditions and methods, operation and use methods, etc. 6.1.2 When the flow meter is subsequently calibrated, the previous calibration certificate shall be provided. 6.2 Identification and nameplate 6.2.1 The flow meter 1. There should be an obvious flow direction identification. 6.2.2 The flow meter should have a nameplate. The nameplate should generally indicate the name, model, factory number, measuring medium, flow range, nominal diameter, accuracy level, maximum operating pressure, power supply voltage, flow sensor material, manufacturer and manufacturing date, manufacturing meter license mark and abbreviation, explosion-proof level (for use in flammable and explosive occasions), and protection level. 6.3 External specifications
6.3.! Newly manufactured flow meters should have a good appearance, with a uniform surface luster and no burrs, scratches, cracks, rust, mildew and shaving. The sealing surface should be flat and free of damage. 6.3.2 The welding parts of the flow meter should be flat and smooth, without welding or desoldering. 6.3.3 The connectors of the flow meter must be externally solid and must not loosen or fall off due to vibration. 6.3.4 The numbers, text and symbols displayed on the flow meter should be clear and neat. 6.3.5 The buttons of the flow meter should have a moderate feel and no adhesion. 6.4 Protection function
For the relevant parameters that can change the metering performance of the flow meter: the flow meter should have a protection function (such as password, etc.). The flow meter or K factor should be consistent with the value of the previous calibration certificate. 6.5 Sealing
The flow meter should maintain the maximum calibration pressure of 5min under the calibration installation conditions, and there should be no penetration or leakage at each connection. 7 Measuring instrument control
Measuring instrument control includes type evaluation, initial inspection, subsequent inspection and in-service inspection. The following is the outline of type evaluation.
7.1 Verification conditions
7.1.1 Requirements for flow meter devices
? 1.1.【The flow standard device (hereinafter referred to as the device) and its supporting instruments should have a valid verification certificate or calibration certificate.
7.1.1.? The mass method device should be preferred, and the volumetric method device and the standard meter method device can also be selected, but the device can provide a mass flow rate that meets the minimum requirement. 7.11.3 When the vapor pressure of the new calibration liquid is higher than the ambient atmospheric pressure, the device should be a closed type. 7.1.1.4 The static pressure of the liquid at any point in the piping system and flowmeter of the device should be higher than its saturated atmospheric pressure. For calibration liquids that are easily vaporized, there should be a certain amount of pressure downstream of the flowmeter. The recommended minimum back pressure is the sum of 1.25 times the saturated vapor pressure of the calibration liquid at the highest test temperature and 2 times the pressure loss of the flowmeter. 7.1.1.5 The mass flow expanded uncertainty of the device should not be greater than 1/3 of the absolute allowable error of the flowmeter. 7.1.2 Calibration fluid
7, 1.2.1 The calibration fluid should be single-phase and clean: without visible particles, fibers and other substances. The fluid should fill the pipeline and flowmeter: the test fluid should be close to the density, viscosity and other physical parameters of the fluid measured by the flowmeter. 7.［.2.2 When the calibration fluid is natural gas: the quality of natural gas shall at least meet the requirements of (GB17820 Class 0 gas, 3
JJG 1038-2008
The relative density of natural gas is 0.55~-0.80. During the calibration process, the gas composition should be relatively stable. Natural gas sampling shall be carried out in accordance with GB/T13609, natural gas composition analysis shall be carried out in accordance with GB/T13610, and natural gas compression factor calculation shall be carried out in accordance with GB/T 17747.2
7.1.2.3 When the H volumetric method is selected, the influence of fluid temperature change on mass flow rate shall be negligible during each calibration process at each flow point.
7.1.3 Calibration environmental conditions
7.1.3. The environmental temperature is generally 5C~~45C; the relative humidity is generally 35%~95%; the atmospheric pressure is generally 86 kPa--. 106 kTa.
7.1.3.2 The AC power source should be (220±22)V, and the power frequency should be (50±2.5)Hz. You can also use a suitable AC or DC power source (such as 24V DC power supply) according to the requirements of the flow meter. 7.1.3.3 The influence of external magnetic field on the flow meter can be ignored. 7.13. The influence of mechanical vibration on the flow meter can be ignored. 7.1.3.5 When the test fluid is a flammable or explosive fluid such as natural gas, the device and its auxiliary equipment, and the test field The ground is empty and full. It is the requirement of GB50251. All equipment and environmental conditions must comply with the safety and explosion-proof requirements of GB3836. 7.1.3.6 During the calibration, all other interferences close to the operating frequency of the flow meter must be eliminated. 7.1.1 Installation of the flow meter
7.1.1.1 The flow meter is installed according to the instruction manual. 7.1.4.2 The flow direction mark of the flow meter is consistent with the flow direction of the fluid. 7.1.4.3 Reduce the influence of the flow meter installation force reduction on the calibration results. 7.1 .4.4 There is no leakage in the connection between the flow meter and the pipeline, and the gasket at the connection does not protrude into the pipeline. 7.1.5 The time for each calibration shall not exceed the minimum measurement time allowed by the flowmeter. 7.1.6 When the output signal of the flowmeter is a pulse, the measurement uncertainty of the number of pulses of the flowmeter in one calibration shall be better than 1/10 of the absolute value of the maximum allowable error of the flowmeter. 7.2 Verification items and verification methods
7.2.1 Verification items
Initial calibration, subsequent calibration and use Items for in-use inspection are listed in Table 2. Items for initial verification, subsequent verification and in-use inspection Item
Random documents
Marking and nameplate
Protective function
Sealing
Accuracy level
Repeatability
Initial verification
Indicates that verification is not required
In-use inspection
JJG 1138—2008
7.2.2 Inspection of random documents, markings and nameplates, appearance, protective function and sealing 7.2.2.1 Check the random documents of the flowmeter, which shall meet the requirements of Article 6.1. 7.2.2.2 Check the markings and nameplates of the flowmeter, which shall meet the requirements of Article 6.2. 7.2.2.3 Check the appearance of the flowmeter, which shall meet the requirements of Article 5.3. 7.2.2.4 Check the protection function of the flowmeter, which shall meet the requirements of Article 6.4. 7.2.2.5 Check the tightness of the flowmeter, which shall meet the requirements of Article 5.5. 7.2.3 Error and repeatability test
7.2.3.1 Connect the equipment, the catering equipment and the circuit of the flowmeter, and preheat the circuit for 30 minutes. With the help of appropriate tools (buttons, manual operation, communication software, etc.), check the settings of the flowmeter parameters (flowmeter factor or K factor, maximum flow, frequency or current corresponding to the maximum flow). If the flowmeter has multiple output signals, the pulse output should be selected for calibration first.
7.2.3.2 The flowmeter is operated at more than 50% of the maximum achievable calibration flow for a period of time, generally not less than 1 minute, and then the zero point is adjusted according to the requirements of the instruction manual. 7.2.3.3 Control of the calibration flow points and calibration times (1) The calibration flow points are 4ax, 0.5n0.2qmar, Qm, 4eux in sequence (2) During the calibration process, the deviation between the actual calibration flow rate and the set flow rate at each flow point shall not exceed +5% of the set flow rate.
(3) The calibration times for each flow point shall not be less than 3 times. For flow meters of type evaluation, the calibration times for each flow point shall not be less than 6 times.
7.2.3.4 Calibration procedures
(1) Adjust the flow rate to the specified maximum flow value and run until the fluid state is stable. (2) Set the device and flow meter to the working state, and operate the device and flow meter to measure at the same time. After running for a period of time, stop the measurement of the device and flow meter at the same time, and record the measurement values of the device and flow meter. (3) Calculate the mass flow measured by the device and flow meter respectively. 7.2.3.5 Calculation of flow meter error
(1) When the flow meter is pulse output, the relative error of a single calibration is calculated according to formula (1): Q = (Q × 100%
Where: , i - the relative error of the first calibration point, %; the cumulative mass flow measured by the flow meter at the first calibration point, kgQ,
(Q.) - the cumulative mass flow measured by the flow meter at the first calibration point, kgQ, calculated according to formula (2):
Where: N, ... the number of pulses output by the flow meter at the first calibration point, K - the K coefficient of the flow meter, 1/kg
When the mass method is used: (Q:), calculated according to the formula or (3): (1)
JJG 1038—2008
(Q,.-(M).,
Wherein: (M), —
mass indication of the scale, t;
-density of the fluid to be verified, kg/m;
\-density of the standard code used for verification, kg/m; density of air, kg/m\.
(2) When the flowmeter is a flow rate ratio, the relative error of the flowmeter in a single verification is calculated according to formula (1): Ee = x 100%
Wherein: 9《--the average indication of the instantaneous mass flow rate of the flowmeter at the i-th calibration point for the first time, kg/(q), --the average instantaneous mass flow rate measured by the calibration device at the i-th calibration point for the first time, kg/h, 9, calculated according to formula (5):
I—Imin
Wherein: I, =the average output current of the flowmeter at the i-th calibration point for the jth time, mA: I..-.-the maximum current value output by the flowmeter, mA; Inin-the minimum current value output by the flowmeter, mA; Imax\—the mass flow rate corresponding to Imax, kg/h. (9): Calculate according to formula (6):
(Q)×3600
Formula (g,
The average instantaneous mass flow rate measured by the αth calibration device at the ith calibration point, k/h; The cumulative mass flow rate measured by the αth calibration device at the ith calibration point, kgt·-The additional time of the 2nd calibration point, %. (3) The sum error of the flowmeter at the ith calibration point is calculated according to formula (7):
Where: E,
The error of the flowmeter at the main calibration point is %; the number of calibrations.
(4) Flowmeter error
The flow error E is +1E"mx
7.2.3.6 Calculation of flowmeter repeatability
(1) Calculation of flowmeter repeatability at the calibration point
According to formula (8):
JJG 1038—2008
Wherein; (E,) ; the repeatability of the ith calibration point,%. (2) Flow meter repeatability
Calculate according to formula (9):
F,=((E),)rnx
Wherein: E, flow meter repeatability,%.
The flow meter error and repeatability meet the requirements of Article 5. (8)
When the flow meter factor needs to be reset after calibration, after setting, recalibrate at .,.. flow points.
7.3 Processing of calibration results
A calibration certificate shall be issued to the flow meter that passes the calibration. A calibration result notice shall be issued to the flow meter that fails the calibration, and the date of the unqualified item shall be indicated. The content requirements of the calibration certificate and calibration result notice are shown in Appendix B. 7. 4 Verification cycle
For level 0.5, it shall not exceed 1 year in general; for level 0.5 and below, it shall not exceed 2 years in general. Appendix A
A.1 Scope
JJG 1038—2008
Outline of type evaluation
This outline is applicable to the type test evaluation of Coriolis mass flowmeter (hereinafter referred to as flowmeter) A. 2 References
The following standards and regulations contain clauses, which constitute the provisions of this regulation through reference. JJF1015--2002 General specification for type evaluation and type approval of measuring instruments G134208-1993 Enclosure protection grade (IP code) GB/T2423.12001 Environmental testing for electrical and electronic products Part 2: Test methods Test A: Low temperature GR/T2423.2-2001 Environmental testing for electrical and electronic products Part 2: Test methods Test B: High temperature C3/T2423.3-2006 Environmental testing for electronic products Part 2: Test methods Test Cab: Hangding damp heat test method
GB/T2423.102008 Environmental testing for power plant electrical products Part 2: Test methods
Test Fc:
Vibration (sinusoidal)
6 Electromagnetic compatibility test and measurement technology Electrostatic discharge immunity test GB/T 17626. 2—2006
GB/T17626.41998 Electrical compatibility test and measurement technology Electrical fast transient pulse group immunity test GB/T17626.5-1999 Electromagnetic compatibility test and measurement technology Surge (impact) immunity test CB/T17626.11·-1999 Electromagnetic compatibility test and measurement technology Voltage drop, short-time interruption and power change immunity test
When using this outline, attention should be paid to the current valid version of the above documents. A.3 Technical documents and test samples for review VIII.3.1 Technical documents
The applicant shall submit technical documents in accordance with the requirements of Article 5.1 of JJF1015 A. 3. 2 Test samples
A.3.2.1 For each type of flow meter, 1/3 of the representative specifications including the minimum diameter shall be selected. A.3.2.2 For each specification of flowmeter, 3 prototypes shall be provided for flowmeters with a diameter of less than 100mm; 2 prototypes shall be provided for flowmeters with a diameter greater than 100mm. A.3.3 If any major defects or deficiencies are found in the technical data review, the data and prototypes shall be returned to the applicant for correction.
AA Legal management requirements
A,4.1 Measurement units
The flowmeter shall adopt legal measurement units. The measurement units of cumulative flow and instantaneous flow are kg and kg/h respectively, the pressure unit is Ma or kPa, the temperature unit is, and the density unit is kg/A.1.2 Accuracy level
The accuracy level of the flowmeter shall meet the requirements of Article 5.1. 8
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