title>Program of Pattern Evaluation of Heating Catalytic Methane Alarm Detector - JJF 1161-2006 - Chinese standardNet - bzxz.net
Home > JJ > Program of Pattern Evaluation of Heating Catalytic Methane Alarm Detector
Program of Pattern Evaluation of Heating Catalytic Methane Alarm Detector

Basic Information

Standard ID: JJF 1161-2006

Standard Name:Program of Pattern Evaluation of Heating Catalytic Methane Alarm Detector

Chinese Name: 催化燃烧式甲烷测定器型式评价大纲

Standard category:National Metrology Standard (JJ)

state:in force

Date of Release2006-12-08

Date of Implementation:2007-01-01

standard classification number

Standard ICS number:17 Metrology and measurement, physical phenomena

Standard Classification Number:General>>Metrology>>A61 Chemical Metrology

associated standards

Publication information

publishing house:China Metrology Press

ISBN:155026-2193

Publication date:2007-01-01

other information

drafter:Chen Fumin, Xu Sanmin, etc.

Drafting unit:National Mine Safety Measurement Station, National Coal Mine Dust and Ventilation Safety Product Quality Supervision and Inspection Center, Coal Industry Chongqing Electrical Explosion-proof Inspection Station

Focal point unit:National Environmental Chemical Metrology Technical Committee

Publishing department:General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China

Introduction to standards:

JJF 1161-2006 Catalytic Combustion Methane Determination Device Type Evaluation Outline JJF1161-2006 Standard download decompression password: www.bzxz.net
This specification is applicable to the type evaluation of catalytic combustion methane determination devices, and other principle and measuring range methane determination devices may be implemented as a reference.


Some standard content:

National Metrology Technical Specification of the People's Republic of China JJF 1161—2006
Catalytic Combustion Methane Determination Device
Program of Pattern Evaluation of HeatingCatalytic Methane Alarm Dctector2006-12-08 Issued
o1 Implementation
The General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China issued IF 1161-26
Catalytic Combustion Methane Determination Device
Program of Pattern Evaluation of HeatingCatalytic Methane Alarm DetectorJJF1161—2006
This standard was approved by the General Administration of Quality Supervision, Inspection and Quarantine on December 8, 2006, and came into effect on January 1, 2007.
Responsible unit: National Environmental Chemical Metrology Technical Committee Drafting unit: National Mine Safety Metrology Station National Coal Mine Dust and Ventilation Safety Product Quality Supervision and Inspection Center Coal Industry Chongqing Electrical Explosion-proof Inspection Station
The exporting unit of this standard is responsible for interpretation
The main drafter of this standard:
Chen Fumin
Participating drafter:
Kong Jingang
Deng Erlin
Lei Libo
Fu Rangtao
JJF1161-2006
(National Mine Safety Training and Measurement Station)
(National Coal Mine Dust and Ventilation Safety Product Quality Supervision and Inspection Center) (National Mine Safety Planning Station)
(National Coal Mine Dust and Ventilation Safety Product Quality Supervision and Inspection Center) [Coal Mine Industry Explosion-proof Inspection Station] (National Mine Shoes Full Quantity Test)
(National Mine Safety Planning Station)
References
3Terms, Symbols, and Translations
4 Overview
Provide certified technical documents and test samples
Provide careful technical documents
5.2 Test samples
Legal management requirements
7 Design requirements
Indication error
Alarm error
Response time
Alarm intensity and signal
Load characteristics
&Technical requirements
8.1 Appearance and electrical inspection.
Long-term stability
1 Position change stability
Continuous time
Environmental suitability|| tt||Insulation resistance.
Insulation uniformity
Suitability of power supply voltage
Error affected by wind speed
Explosion-proof equipment
Evaluation environment
Conditions and methods for type evaluation
Conditions for type evaluation
Methods for type evaluation
Treatment of results of type evaluation
Judgment principle
Evaluation report
F1161-2006
Record A Type evaluation report for catalytic combustion methane tester 1
1 Scope
JF 1161---2006
Outline for type evaluation of catalytic combustion methane tester This specification is applicable to the type evaluation of catalytic combustion methane tester (referred to as tester), and methane testers of other types and ranges shall be implemented for reference.
References
GB/T2423.1-2001 Environmental testing for electrical and electronic products Part 2: Test methods Test A: Low temperature GB/T2423.2-2001 Environmental testing for electrical and neutron products Part 2: Test methods Test B: High temperature GB/T2423.4—1993
GB/T 2423.5—1995
GB/T 2423.8--1995 Basic environmental test procedures for electric and electronic products Test Db: Cyclic damp heat test method Environmental testing for electric and electronic products Test: Shock Test Part 2: Test method Test Ea and conduction Test Part 2: Test method Test Ed: Environmental testing for electric and electronic products by drop 5 Environmental testing for electric and electronic products Part 2: Test method Test Fc and conduction GB/T 2423.10—1995
rule: vibration (sinusoidal)
GB3836.1-2000 Electrical apparatus for explosive gas atmospheres Part 1: General requirements GB3836.4--2000 Electrical apparatus for explosive gas atmospheres Part 4: Intrinsically safe "\G84208--1993 Enclosure protection grade (IP code) JJG678-199G Calibration procedure for catalytic combustion type alkanes tester GB13486-2000 Portable thermal catalytic alkanes detection alarm When using this specification, please pay attention to the use of the current valid versions of the referenced documents. 3 Terms, symbols, codes
Long-term stability: Under the specified working conditions and time, the zero point, calibration point and alarm point of the tester remain within the allowable change Performance within the chemical range.
4 Overview
The measuring instrument uses carrier thermal catalytic cooling, and the measuring bridge is composed of carrier catalytic elements. When methane gas exists in the environment where the measuring instrument is located, methane produces flameless combustion on the surface of the catalyst, causing the resistance of the catalytic element to change, and the bridge circuit is unbalanced to produce an electrical signal output. The size of the signal is linearly proportional to the methane content, thereby realizing the detection and alarm of the methane content. The measuring instrument is mainly composed of a methane catalytic element, a bridge, an amplifying circuit and secondary instruments.
The measuring instrument is mainly used in mines and other places with explosive methane gas. There are two types: portable and fixed (also known as methane sensors). It is mainly used for the measurement and alarm of methane content in the air. When the methane concentration reaches the set alarm, 1161—2006
When the alarm point is reached, it can send out sound and light alarm signals. The extended methane detector can also output electrical signals corresponding to the methane concentration, connect with other equipment, realize the on-off control of the electrical equipment in the monitored area and the remote monitoring of the methane degree, 5 Provide technical documents and test prototypes for review 5.1 Provide technical documents for review
5.1.1 Prototype photos;
5.1.2 Product enterprise standards (including inspection methods): 5.1.3 General assembly drawings, card parts drawings and circuit diagrams; 5.1.4 Reliability design, intrinsic safety calculation book; Instructions for use:
5.1.6 Test reports made by the research and development unit. 5.2, Test prototype
4 sets of prototypes and auxiliary accessories (such as battery packs for the detector, plastic plates for ABS shells, etc.) produced by the applicant should be provided. :When the performance test and explosion-proof test are conducted by two technical institutions respectively, the prototypes shall be sent to the technical institution for performance test, and then the technical institution for performance test shall be entrusted with explosion-proof test to ensure the consistency of the two test prototypes.
Legal management requirements
No measuring instrument shall adopt illegal units of measurement, and the metrological performance of the measuring instrument must comply with the provisions of the national verification regulations. 6.2
6.3 Marking and abbreviation generally include the following contents: type approval mark and number of measuring instrument (this item is not mandatory, and the corresponding space can be reserved for new products); 6.3.1
6.3.2 Manufacturing measuring instrument license mark and number (the corresponding space can be reserved for new products, only for domestic instruments); 6.3.3 General identification should include the following contents:
The measuring instrument should be marked with the name, model, measuring range, number, manufacturing date, manufacturing unit, explosion-proof EX mark and number. The coal mine should also be marked with the coal safety mark and number. The domestic measuring instrument should also be marked with the manufacturing measuring instrument license mark and number:
7 Measurement requirements
7.1 Indication error
When the measuring range is (0--4.00)%CH, it should meet the requirements of Table 1; for fixed measuring instruments, the output signal should also meet the requirements of Table 1 after being converted into methane value. Table 1 (H~4.00)%CIl, indication error measurement range/%,CH
segment/%CH,
basic error/%CH
7.2 Alarm error
..IF 1161--2006
The alarm point of the measuring instrument should be able to be set arbitrarily within the range of (0.50~2.00)%CH: The alarm point error should meet the requirements of Table 2: For fixed measuring power, its output signal should also meet the requirements of Table 2 after being converted into methane value. Table 2 Alarm error of measuring instrument
Alarm point range/%(H,
Alarm error/%(H
7.3 Ah Fu time
0.50--1.00
±10% of the standard value
For the measuring device with continuously working detection element, the response time shall not be greater than 10.20$For the measuring device with discontinuous working detection element, the response time shall not be greater than 15sa
7.4 Drift
The drift of the measuring device shall not exceed the zero drift and the indication drift. The zero drift shall not exceed ±0.10%CHI, and the indication drift shall not exceed 10.20%CH9
7.5 Alarm intensity and signal
The alarm sound level intensity of the portable measuring device shall not be less than 75dB (A); the alarm sound level intensity of the fixed measuring device shall not be less than 80B (A): the alarm light signal can be clearly seen at 20m in the dark. 7.6 Load characteristics
For the fixed measuring of the output frequency and current signal, when the external load voltage changes in the range of (0~500)Ω, the change of the methane concentration conversion value shall not exceed the provisions of Table 1. 8 Technical requirements
8.1 Appearance and power-on inspection
8.1.1 The readout part should be set on the visible part of the measuring instrument; the readout part should be clear and easy to identify, and the portable measuring instrument should have a lack of indication;
8.1.2 The indicator should be clear and can show positive and negative values, and its resolution should not be lower than 0.01%CH; 8.1.3 The appearance of the measuring instrument should not have mechanical damage, the structure should be complete, the accessories should be complete, the adjustment knobs should be able to adjust normally, the operating buttons should be light and flexible, and the positioning should be accurate: 8.2 Long-term stability
Accurate stability During the qualitative test, the indication error and alarm error of the measuring instrument shall meet the requirements of Articles 7.1 and 7.2 of this outline.
8.3 Adaptability to position change
During the position change test of the portable measuring instrument, when the measurement range is (0~4.00)%CH., the position error of the display value or alarm point shall not exceed 10.02%CH.8.4 Continuous working time
After the portable measuring instrument has been working for 10 hours, there shall be no undervoltage, and the indication error and alarm error shall meet the requirements of Articles 7.1 and 7.2.
8.5 Environmental adaptability
8.5.1 Working temperature test
JIF 1161—2006
Upper limit of working temperature: 40t, lower limit of working temperature: t, duration: 2h. During the test, the indication error and alarm error of the measuring instrument shall meet the requirements of Articles 7.1 and 7.2 of this outline. 8.5.2 Storage temperature test
Storage temperature upper limit 60, storage temperature lower limit -40℃, duration 16h, after the test, restore in the quasi-positive environment for 2h, the indication error and alarm error of the measuring instrument shall meet the requirements of Article 7.1 and Article 7.2 of this outline. 8.5.3 Vibration test
Severity: frequency range (111--150) Hz, acceleration 50m/s3 (5g); number of sweep cycles on each axis 10 times: after the test, the appearance, indication error and alarm error of the measuring instrument shall meet the requirements of Article 8.1, Article 7.1 and Article 7.2 of this outline,
8.5.4 Market elimination test
Severity: peak acceleration 500m/s2 (50g): pulse duration (6±1) ms; after the test, the appearance, indication error and alarm error of the measuring instrument shall meet the requirements of Article 8.1, Article 7.1 and Article 7.2 of this outline. 8.5.5 Drop test
After the drop test at a height of 0.5m, the appearance, indication error and alarm error of the measuring instrument shall meet the requirements of Articles 8.1, 7.1 and 7.2 of this outline.
8.5.6 Transportation test
The measuring instrument simulates the transportation test time for 2h. After the test, the appearance, indication error and alarm error of the measuring instrument shall meet the requirements of Articles 8.1, 7.1 and 7.2 of this outline. 8.5.7 Alternating damp heat test
Severity: Temperature 40℃: Cycle 6d; After the test, they are restored in a normal environment for 2h. The appearance, indication error, alarm error, insulation resistance and insulation strength of the measuring instrument shall meet the requirements of Articles 8.1, 7.1, 7.2, 8.6 and 8.7 of this outline. 8.6 Insulation resistance
After the alternating damp heat test, the insulation resistance of the measuring instrument shall not be less than 1.5MQ8.7 Insulation strength
After the alternating damp heat test, the measuring instrument shall withstand 500V, 50Hz AC voltage, and there shall be no breakdown or flashover within 1 minute.
8.8 Power supply voltage adaptability
For portable measuring instruments, when the working voltage is just under the voltage indication, for fixed measuring instruments, when the power supply voltage is (9~24)V respectively, the indication error and alarm error shall meet the requirements of Articles 7.1 and 7.2. 8.9 Wind speed influence error
The wind speed influence error of the measuring instrument with a measuring range of (0·4)%CL shall not be greater than ±0.1%CH4. 8.10 Explosion-proof type
8.10.1 The explosion-proof type of the measuring instrument is the intrinsically safe and flameproof type for mining use, and its explosion-proof performance shall comply with the provisions of GB3836.1-2000, GB3836.4-2000 and MT28--2005. It shall be qualified by the explosion-proof inspection agency authorized by the state.
JJF 1161--2006
8.10.2 The electrical clearance, creepage distance and distance of the printed circuit board under the insulating paint layer of the measuring instrument shall comply with the requirements of GB3836.4--2000. When the outer surface of the measuring instrument is made of non-metallic materials, the surface insulation resistance shall not be greater than 1G2. 8.10.3
The maximum surface temperature of the measuring instrument is 150t:
8.10.5 The components of the circuits related to the intrinsic safety performance of the measuring instrument shall not exceed one third of the maximum current, voltage and power specified in the component installation conditions and temperature range under normal operation and specified fault conditions. 8.,10.6
After the explosion-proof drop test in accordance with the provisions of GB3836.1-2000, the measuring instrument shall not have any deformation or damage that may affect the explosion-proof performance.
The specification is that the
measuring instrument should pass the GB30OHd
test: the catalytic ceramic used in the
measuring instrument should obtain explosion-proof certificate and relevant supporting documents.
Performance reaches IP54
Protection of measuring instrument
Type evaluation items
Wu Ping price items should include
Type evaluation items of measuring instrument
Indication error
Alarm error
Response time
Degree and signal:
Negative characteristics
Appearance and power-on inspection
Long-term stability
Adaptability to working position changes
Continuous working time
Insulation resistance
Insulation strength
And items
Portable methane
Design requirements
Fixed methane
Measuring instrument
Technical coverage|| tt||Importance
Type evaluation items
Supply voltage adaptability
Wind speed shadow error
Working temperature lower limit
1. Operating temperature upper limit
Storage temperature lower limit
Storage temperature upper limitbZxz.net
Alternating damp heat test
Vibration test
Impact test
Transportation test
Drop test
Explosion structure,
Parameter inspection
Spark test
Maximum surface temperature test
Shell anti-expansion performance test
Plastic shell insulation resistance test
Explosion-proof drop test
JJF1161--2006
Table 3 (Continued)
Portable methane
Measurer
Technical requirements
Explosion-proof safety
Note "" indicates the items to be inspected, "×" indicates the conditions and methods for type evaluation
10.1 Conditions for type evaluation
10.1.1 Environmental conditions
Fixed methane
Measurer
Indicates the items that are not required to be inspected.
Importance classification
Environmental temperature (15~35)℃, passive is not more than ±2℃; environmental relative humidity <85%, and there is no interfering gas in the surrounding air that affects the detection.
10.1.2 Testing equipment
JF 1161—2006
The testing equipment for the metrological working performance of the measuring instrument shall be selected in accordance with the requirements of JJG678-1996. 10.1.2.1
Insulation tester: input voltage 500V, accuracy level 10. 10.1.2.3 Endurance tester: AC voltage (01500)V, frequency 50Hz, accuracy level better than 5, 10.1.2.4 Multimeter: (030)V, (030)mA, 1.Level 5. Frequency Lang: (0~10000)Hs, resolution 1Hz.10.1.2.5 3
DC regulated power supply: (0--30)V, 1A
10.1.2.7 Environmental condition test equipment shall comply with the requirements of (B/T2423.1~GB/T2423.10, 10.1.2.8
Wind tunnel for wind speed test: wind speed range (0-30)m/s, good sealing, smooth stability test standard deviation reaches 1,0%, observation window and adjustable direction measuring device fixing frame shall be set. 10.1.2.9 The equipment for explosion-proof performance inspection shall comply with the requirements of GB3836.1-2000 and GB3836.4--2000. 10.2 Methods of type evaluation
10.2.1 Appearance and power-on inspection
Instrument and daily inspection.
10.2.2 Indication error
10.2.2.1 Instrument calibration
Portable instruments use local power supply. Fixed instruments use The DC regulated power supply is used, and the arrangement of the 4-core aviation socket on the fixed instrument is shown in Figure 1.
Power supply positive pole socket No. 1
Central source negative pole-socket No. 2
Transmission-socket No. 3
Room socket-socket No. 4
Figure! Schematic diagram of socket arrangement on fixed instruments Connect the power supply, the instrument preheats for at least 15 minutes, and calibrate the instrument zero point with clean air according to the flow rate required by the manual, and pass 1.1%CH. Standard gas to calibrate the instrument indication. 10.2.2.2 Indication error
10.2.2.2.1 Portable instrument
According to the flow rate required by the instrument manual, pass about 0.5%CH4, 1.5%CH4, and 3.0%CH4 standard push gas, and read the stable indication of the instrument. Do it 3 times for each point, and take the arithmetic mean as the indication of each point of the instrument. Calculate the indication error according to formula (1), and the result cannot exceed the provisions of Table 1. AX = X X.
Wherein; x is the average value of three indications: X. — standard value of methane.
10.2.2.2.2 Fixed instrument
Connect an external 00 load resistor to the instrument, and pass about 0.5% CIL, 1.5% CH4, and 3.0% CH4 methane standard gas respectively according to the flow rate required by the instrument manual, and read the methane concentration value displayed on the instrument: At the same time, read the electrical signal value of the corresponding methane concentration output at the instrument input and output terminal (socket No. 3) and the negative terminal of the power supply (socket No. 2). Do it 3 times for each concentration point. And convert the electrical signal value into the methane concentration value according to formula (2), and take the arithmetic mean as the concentration indication value at each point. The maximum difference between the indication value and the standard value should not exceed the provisions of Table 1. (Gm- Go) ×(P, - Pa)
(PP.
Wu Zhong: G
Detection output signal P: corresponding methane volume fraction, %CH: (2)
The methane volume fraction value corresponding to the upper limit of the output electrical signal, %(H, according to the manual of the model under test, the fixed value of the test is given;
fixed value;
The output of the test is unstable, (IIz, mA); thank the upper limit standard
Output telecommunications
Output electrical
Lower limit of confidence range
10.2.3 Drift
After charging the stool agitator, the continuous
CH, methane standard gas value
The zero point of the instrument
is calculated according to formula (3):
In the formula: X
Record the value of each measurement
According to the manual of the inspected model
The manual of the inspected model gives a fixed value:
The manual of the inspected model gives a fixed value.
Introduce clean air and the indication of about 3.0%
point, and make a total of:
The maximum deviation of the zero point measurement values ​​of 5 times
is expressed. The maximum value of the instrument's indication every day is about 3.0%--the zero value of the first measurement; the maximum deviation between measurements is about 3.0%--take 5 times. 10.2.3.2 Fixed transmitters should work normally. After 24 hours, measure the zero point of the instrument and the display value of the methane standard gas. The zero point and the display value of the methane standard gas should comply with the provisions of Article 7.4 of this outline: The zero point and the drift of the methane standard gas should be about 3.0%--the zero point and the display value of the methane standard gas should be about 3.0%--the maximum deviation between measurements is about 3.0%--take 5 times. The maximum deviation between the indication measurement value at the 3.0% point and the value at the instrument is the maximum deviation between the indication measurement value and the value at the instrument.
10.2.4 Alarm error
%CHL The indication at the zero point is the indication of the instrument. Zero point measurement
(4) Calculation. Indication measurement
According to the instrument instructions, set the alarm point at 1.0%: Pass the instrument through a methane standard gas of about 1.1% CH4 and read the alarm value. Repeat the operation 3 times, take the average of the three times as the instrument alarm value, and calculate the alarm error according to formula (4).
In the formula: A——Alarm setting value;
A——Alarm average value.
10.2.5 Response time
After the instrument is stable, pass a methane standard gas of about 3.0% CH4 and read the stable indication of the instrument: Use a clean 8- Pa)
(PP.
Wu Zhong: G
Detection output signal P: corresponding methane volume fraction, %CH: (2)
The methane volume fraction value corresponding to the upper limit of the output electrical signal, %(H, according to the instruction manual of the model being tested, the test
fixed value;
fixed value;
The output of the test signal is unstable, (IIz, mA); upper limit standard
output telecommunication
output electrical
signal range lower limit standard
10.2.3 Drift
After charging the agitator, continuous
CH, methane standard gas value||t The zero point of the instrument is calculated according to formula (3): Where: X is recorded in the value of each measurement according to the manual of the model under test. The fixed value is given in the manual of the model under test. The fixed value is given in the manual of the model under test. The value of the zero point is about 3.0% when clean air is passed through. The maximum deviation of the zero point measurement values ​​of 5 times is expressed. The maximum value of the instrument's indication P is about 3.0% for each day. The value of the zero point is about 3.0% for each day. The value of the zero point is about 3.0% for each day. 10.2.3.2 Fixed transmitters should be operated normally for 24 hours and then measure the zero point of the instrument again. The measured value of the methane standard gas should be about 3.0%; the displayed value of the methane standard gas should be about 3.0%. The displayed value of the methane standard gas should comply with the provisions of Article 7.4 of this outline: 1 hour, 8 hours, and 2 hours should be cleared before and after the zero point and the displayed value should be about CH3. The maximum deviation between the zero point and the displayed value at the 3.0% point of the instrument should be about 3.0%. 10.2.4 Alarm error %CHL The indication at the point,
Only the indication of the instrument. Zero point measurement
(4)Calculation. Indication measurement
According to the instrument instructions, set the alarm point at 1.0%: Pass about 1.1% CH4 methane standard gas into the instrument and read the alarm value. Repeat the operation 3 times, take the average of the three times as the instrument alarm value, and calculate the alarm error according to formula (4).
Where: A——Alarm setting value;
A——Alarm average value.
10.2.5 Response time
After the instrument stabilizes, pass about 3.0% CH4 methane standard gas and read the stable indication of the instrument: Use a clean 8- Pa)
(PP.
Wu Zhong: G
Detection output signal P: corresponding methane volume fraction, %CH: (2)
The methane volume fraction value corresponding to the upper limit of the output electrical signal, %(H, according to the instruction manual of the model being tested, the test
fixed value;
fixed value;
The output of the test signal is unstable, (IIz, mA); upper limit standard
output telecommunication
output electrical
signal range lower limit standard
10.2.3 Drift
After charging the agitator, continuous
CH, methane standard gas value||t The zero point of the instrument is calculated according to formula (3): Where: X is recorded in the value of each measurement according to the manual of the model under test. The fixed value is given in the manual of the model under test. The fixed value is given in the manual of the model under test. The value of the zero point is about 3.0% when clean air is passed through. The maximum deviation of the zero point measurement values ​​of 5 times is expressed. The maximum value of the instrument's indication P is about 3.0% for each day. The value of the zero point is about 3.0% for each day. The value of the zero point is about 3.0% for each day. 10.2.3.2 Fixed transmitters should be operated normally for 24 hours and then measure the zero point of the instrument again. The measured value of the methane standard gas should be about 3.0%; the displayed value of the methane standard gas should be about 3.0%. The displayed value of the methane standard gas should comply with the provisions of Article 7.4 of this outline: 1 hour, 8 hours, and 2 hours should be cleared before and after the zero point and the displayed value should be about CH3. The maximum deviation between the zero point and the displayed value at the 3.0% point of the instrument should be about 3.0%. 10.2.4 Alarm error %CHL The indication at the point,
Only the indication of the instrument. Zero point measurement
(4)Calculation. Indication measurement
According to the instrument instructions, set the alarm point at 1.0%: Pass about 1.1% CH4 methane standard gas into the instrument and read the alarm value. Repeat the operation 3 times, take the average of the three times as the instrument alarm value, and calculate the alarm error according to formula (4).
Where: A——Alarm setting value;
A——Alarm average value.
10.2.5 Response time
After the instrument stabilizes, pass about 3.0% CH4 methane standard gas and read the stable indication of the instrument: Use a clean 8
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.