Some standard content:
Verification Regulations of the People's Republic of China for Metrology JJ971—2002
Liquid Level Measuring Devices2002—09-13 Issued
Implementation on 2002—12— 13
National Quality Supervision, Inspection and Quarantine General issued
JJG 97
Verification Regulations of
fheLiguid Level Measuring DevicesJIG971-2002
This regulation was approved by the General Administration of Quality Supervision, Inspection and Quarantine on September 13, 2002, and came into effect on December 13, 2002.
Responsible unit: National Pressure Metrology Technical Committee Main drafting unit: Shanghai Jitong Testing Technology Research Institute This regulation is entrusted to the National Pressure Metrology Technical Committee to interpret this regulation. Main drafters
Zhu Jialiang
Tu Limeng
JJG971·202
(Shanghai Jitong Testing Technology Research Institute) (Shanghai Jitong Testing Technology Research Institute) 1
Applicable literature
Terms and definitions
Set point discussion
Switch-
Measuring Performance requirements
Indication error
Stability
Liquid level signal error
Setting delay error bzxZ.net
Switching difference
6 General technical requirements
Influence of large power supply changes
Ambient temperature influence
Model disturbance
Industrial magnetic field resistance
Static discharge resistance
Time-dependent magnetic field resistance
Electrical fast transient pulse resistance
J: 971—2(H2
Voltage drop, whole hole interruption immunity performance withstand voltage tightness
Insulation resistance
Insulation constant
（1）
（3）
（3）
6.13 Transport storage adaptability
Anti-operation performance
7 Wall device control
Type setting or prototype test
JIG 971—2002
First calibration: Subsequent calibration and in-use inspection: 7.2
7.3 Handling of calibration results·
7.4 Calibration cycle·
Appendix A Type certification test plan and test method Appendix B Format of calibration certificate for level gauges
Format of calibration certificate
(5))
1 Scope
J1C971—2002 02
Verification Procedure for Liquid Level Meters
This procedure applies to the verification of liquid level meters, prototype test: initial verification, subsequent verification and in-use inspection. The types of liquid level meters include selector type, ball type, float type, pressure support type, penetration type, guide type and reverse forward verification type, etc. Liquid level meters manufactured using other principles should refer to this procedure for verification: 2 References
The following references are cited:
JF 1001—1998
JF1015—2002
JJF 1016--2002
FJG 617-: 1956
JG 882--1994
General terms and definitions for road measuring instruments
Type evaluation and type standard for road measuring instruments
Guidelines for the compilation of type evaluation of road measuring instruments
Verification procedure for pressure transmitters
GB/I 17626.2--1998
G3/T 17626.3--1908
GB/T 17626.4—1998
GB/T 17626.8—1998
GB/- 17626.11—1999
Stationary film change medium disturbance test
Frequency medium magnetic pickup patch immunity test3
Electric fast transient pulse group immunity test
Engineering field engine disturbance test
Voltage station drop, short-time interruption and voltage change immunity test. JR/T9329—1999
Basic environmental conditions for transportation and storage of positioners and meters When using this regulation, the safety regulations shall be followed! The regulations of the referenced documents shall be valid versions. 3 Terms and definitions
3.1 Set point differential
The difference between the actual level measured and the level setting value when the variable meets the specified requirements. .2 Switching gap
The input (excitation) gap obtained when the output state changes from one state to another in the switching operation (or downstream operation) of a dual level meter.
3.3 Switching gap
The difference between the switching points of the same set point and the downstream operation. 4 Transmission
Liquid level is an industrial process measurement, display and control standard. The instrument used to indicate and control the level in the system can be divided into two categories according to its function: remote level gauge, which usually transmits the liquid level status of the field to the place to be monitored by means of or electrical signals, or uses a level transmitter. 971—2002
The liquid level is usually controlled by a position control method. The liquid meter is usually composed of three parts: a sensor, a converter and an indicator. There are two types of liquid level measurement: the float level measurement principle. The liquid level measurement requires an internal detection method. The float on the vertical displacement element is used to observe the liquid level (such as float type, float type: h) float level measurement principle. The position is measured by detecting the position of the float. The position of the float can be detected by magnetic, optical, acoustic, strong radiation and other methods. (female 1 invitation float type:) float scraping cable type child holding measurement principle. The position of the buoy is directly measured by the pulley of the buoy, and the data is transmitted to the indicator by mechanical means through a cable, a pulley or a cam assembly. For example: The position of the liquid is measured by measuring the pressure difference between two points below the liquid surface. For example: Ultrasonic and microwave level measurement products: Principle: By detecting a short beam of energy, the device emits it to the surface and determines the liquid level at the same time (such as branched type: "gamma ray wave position measurement" Principle, the liquid absorbs gamma radiation when it is in the presence of a radiation source and is measured by the detector (such as radiation type); Principle of level measurement, the liquid level of the concentrated body is measured by the electrical penetration of the particle wave between two electrodes such as capacitance type! :
Principle of level measurement: The liquid level of the concentrated body is measured by detecting the resistance of the two electrodes separated by the body (such as conductivity type):
5 Measurement performance requirements
5.1 Indication error
Level meter indication value The maximum allowable error can be expressed in different ways: a) The maximum allowable error of the indication is (+
where N can be 0.02, 0.03), 0.05, .10.2, 0.51., 1.5, .0, 2.5; Fs is the sum of the flowmeter, em or mn;
Consider the analysis of the digital indicating level gauge: find a. Analog indicating level gauge =: The maximum allowable error of the indication is
where N is directly expressed in units of length, un5 .2 The error of the level gauge should not exceed the maximum allowable error of the indication. Among them, the error of the level gauge and the pressure gauge should not exceed the maximum allowable error of the indication. 5.3 Stability
The level gauge with medium power supply can continue to work for 24 hours, and the indication accuracy still meets the requirements of 5.1. 5.4 The error rate of the output of the level signal
The error rate of the level gauge with transmitter function should not exceed + (%) of the output process. 2
J $712002
Where:. Can be 0.2, 0.5.1.01.5, 2.0.2.5. 5.5 Set point error
For level gauges with position control, the set point setting limit is three FS or one) where: a can be 0.1.0.2, 0.5, 1.0, 1.5.2.0, 2.5; N is the error limit expressed in linear units, n or. 5. For level gauges with
and position control, the error shall not exceed 2 times the set point setting limit. 6 General technical requirements
6.1 Appearance
) The name or trademark of the manufacturer, product unit and certificate number of the liquid level gauge should be marked on the front: the model specification, maximum allowable setting error, range, (rated working pressure), production number, year of manufacture and manufacturing license mark and number of measuring instruments should be marked on the nameplate of the liquid level gauge. New products should carry type approval mark and number: nameplate information should be easy to lose:
) The words, numbers and symbols on the nameplate of the liquid level gauge terminal should be accurate, clear and should not be incomplete:) For digital level gauges, the brightness of the display should be uniform and there should be no missing phenomenon. The sequence of the double display should not be less than 1/5 of the maximum allowable error. 6.2 Main power supply
For the level gauge with power supply, the power supply varies from 187V to 242V, 47.5Hz to 52.51Hz; when the current supply changes by ±10% of the rated voltage, the indication of the level gauge shall not exceed one-half of the absolute value of the maximum permissible error.
6.3 Environmental influence
For the level gauge without power supply: under the condition of ambient temperature 15: -15, relative humidity 45%-75%, the evaluation error shall meet the requirements of 5.1.
For the level gauge with power supply, the ambient temperature must be 15: -15, relative humidity 45%-75%. -60)" change, the display of each change of 0 makes the change not exceed the absolute value of the maximum allowable setting error. 6.+! Common mode interference response
When there is an AC power supply before the input end is insulated from the ground, a new common mode interference voltage of 250VSH2 is applied between the input end and the battery, and the change of the indication value of the level meter should be less than half of the absolute value of the maximum allowable error. 6.5 Power frequency dense field immunity performance
The level meter with power supply can still work normally in the environment of 5 degrees specified in GB17626.8-t998, and the performance of the meter should still meet the requirements of 5.1. 6.6 Electrostatic discharge thermal performance ||t t||With power supply level stop: In the environment of level 3 specified in 17626.2-1998, the performance or performance of the equipment is allowed to be temporarily reduced or lost, but can be restored: 6. The RF interference performance has the assumption that the power supply is provided! In the environment of the severity level of 2 specified in /T17626,3-198, the performance or performance of the equipment is allowed to be temporarily reduced or lost, but can be restored, and the performance of the equipment can also be quickly reduced: In the environment of level 3 specified in (17626,11958, the performance or performance of the equipment is allowed to be temporarily reduced or lost, but can be restored, and the performance of the equipment can also be quickly reduced: In the environment of level 3 specified in (17626,11958, the performance or performance of the equipment is allowed to be temporarily reduced or lost, but can be restored, and the performance of the equipment can be quickly reduced: In the environment of level 3 specified in (17626,11958, the performance or performance of the equipment is allowed to be temporarily reduced or lost, but can be restored, and the performance of the equipment can be quickly reduced There is a temporary loss of energy, but it can recover by itself. 5.9 The pressure circuit and the power supply are interrupted at the point. In the case of a temporary loss of energy, the energy can be restored by itself. F126.1:1 The energy can be restored by itself within the specified time. The system is connected, and the instrument must be effective.
6.10 The total pressure of the liquid meter should be directly subjected to the pressure of the medium and the commercial sealing test should be carried out. The working shell, float and float of the position meter should be less than 5 UM; the working shell, float and float of the position meter should be equal to 1DPa. The float should be able to withstand 1.25 times the rated pressure. No leakage or damage should occur.
6.11 Insulation. Risk
Only the power supply before the level gauge is rolled: In the environment training time 1535: The humidity is 5-15, the liquid! The source of the liquid is not guaranteed under the condition of reducing the external power supply. MM.12 Carbon intensity
The useful source of the liquid level gauge, under the condition of not increasing the box gain 15℃-35, the sea thickness is 45%-75, the power supply of the meter, the connection are all brought to (or the external company to apply the test pressure specified in Table 1, and maintain"ir: The setting is more than one arc,
No dead capacity electric display
(3 . - 130
130 t350
513 Operation and maintenance of the product in the city
teaching position can be subjected to the "19 effect" 19 medium temperature, low temperature, humidity, touch control end drop, high temperature 55, low temperature 40, drop point 100mm250mm: (meal. Also the temperature can be tested, the high temperature 55 test can not be carried out.) After the original test, there is no damage, the electrical insulation can still meet the requirements of 5.1, 5.2.5.56.1
5.E4 Anti-drying performance
JJG 9712002
Only the explosion performance must meet the requirements of the corresponding operating level. ? Measuring instrument control
meter to solve the instrument to dig cattle package to support the military type tight war prototype test, road modification verification, after slow pull and warranty test, 7.1 fall type or companion test
home type or sample visual test should be carried out safely: one meter only type evaluation you and type support standard road use regulations and (62 product Huixian type evaluation outline end guide to Hui request,! Test port and method see the record A: there are industry liquid manufacturing you according to! The principle of the system needs to add some performance requirements, then according to the relevant beauty intelligence
7.2 before reaching verification, after picking up and Germany see city inspection 7.2.1 magic determination relatives
7.2.1. 1. Checking equipment
The filter that can be used is matched with the equipment. The type of micro-test is called the combination of 2. Select from the following combinations: flow meter, standard method, including the expansion uncertainty of the entire test note, the dynamic range of the small over-meter, the maximum allowable value of the liquid level meter being tested, 14-1. The name of the wave is
current control device, new control device, standard, water level, family production, needle determination and registration market
standard H current 1 current technical ability
stand-alone current meter
standard Ze general reliable
absolute plan
technical requirements
high H = (U ~2 000)mrr.
The allowable error of the product is ±0.35.
(0.-20)m
(0--20)m
(G ~ 30)mA
.J2D.U5 level
0.02 level, 0.0S level
s -/ mp
Transmission voltage: 5007: 10 level
Reading of display bar
Output point type re-position meter hold time total current pre-position fee special type position meter specified positive analog wave signal engineering specification liquid transmission display small setting table state
Item policy wave should be calculated output signal city
Testing construction electrical liquid level meter leaf supply analog liquid level test pool rise power
Instrument name
And voltage test instrument
Previous Lan power test equipment placement
7.2.1.2 Environmental conditions
JJC971~2002
Table 2 [thread]
Technical requirements
Output power: AC (-1S
4: (45 - 55) 1Iz
Efficiency: low 25
H: 15 level
Environmental temperature: 2015C:
Relative humidity: 43%-75%.
7.2:1.3Other conditions
Test continuity
: Durability and airtightness test
Power supply: Liquid power supply, the power supply shall not exceed +1% of the rated value: The power supply shall not exceed 1% of the rated value,
7.2.2Test date
First test, The calibration items for subsequent calibration and inspection during use are shown in Table 3. Table 3: Inspection items: Insulation resistance Insulation strength Indication error 5.4 Limit signal input 5.5 Change of setting point 5.n Switching point: “+” indicates a setting point, which has been calibrated before. “Continued calibration” indicates that the next calibration is not allowed, and the calibration must be carried out according to the actual situation after the calibration. JHG9712002 Note: The position meter must be calibrated before the calibration, and the uncertainty assessment technique must be used. And the new parts, the standard involves the cavity vertical basis is not the given L standard under the control of the instrument error range for this room! /4-1, can only be carried out on-site adjustment, 7.2.3 Verification method
7.2.3.1 Appearance inspection
Use force test and through the test, it meets the requirements of 6.1. 7.2.3,2 Pressure and other testers
Install the small front pressure part of the rolling position under the pressure test equipment, apply the pressure specified in 6,0 for 5m. Observe whether there is leakage or damage,
7.2.3.3 Verification of indication difference
The power supply of the filter meter is powered on, unless the manufacturer specifies, the time item is 15ni.
Select calibration points: The calibration points should be selected according to the layout of the process, generally including the upper and lower limits.
Error calculation process data processing principle. The number of digits after the decimal point should be limited to the maximum allowable setting error of the level meter by 1/10.1-20 (equivalent to 1 more decimal place than the maximum allowable setting error): The maximum error of the digital level meter and the error after calibration are calculated and multiplied, and the last digit should be aligned with the last digit of the display of the level meter. Whether the new instrument is qualified should be based on the data after verification: The calibration method of the level meter water tank must be used for finalization (or prototype test) and the first calibration and arbitration calibration. First, install the level meter as set and the water tank 1 (as shown in Figure 1). During installation, the level meter should be vertical to the horizontal plane with a deviation of no more than 1. When selecting the calibration point, the person in charge should check the liquid gauge at 2m, and then choose the appropriate level of 2. The float is too
port micrometer
change to liquid level
indicator
calibration water tank
dense water waves
Figure 1 calibration installation drawing
medical
night level gauge
liquid level!
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