JJG 635-2011 PDF in English
JJG 635-2011 (JJG635-2011) PDF English
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Verification Regulation of Carbon Monoxide and Carbon Dioxide Infrared Gas Analyzer
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Standards related to: JJG 635-2011
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JJG 635-2011: PDF in English JJG 635-2011
JJG
NATIONAL METROLOGICAL VERIFICATION REGULATIONS
OF THE PEOPLE’S REPUBLIC OF CHINA
Carbon Monoxide and Carbon Dioxide Infrared Gas
Analyzer
ISSUED ON: SEPTEMBER 14, 2011
IMPLEMENTED ON: MARCH 14, 2012
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China
Table of Contents
1 Scope ... 5
2 Overview ... 5
3 Metering performance requirements ... 5
3.1 Detection gas, indication error, repeatability and response time ... 5
3.2 Drift ... 5
3.3 Non-measured component interference error ... 6
4 General technical requirements ... 6
4.1 Appearance ... 6
4.2 Insulation resistance... 6
4.3 Insulation strength ... 6
5 Measuring instrument control ... 6
5.1 Verification conditions ... 7
5.2 Verification items ... 8
5.3 Verification methods ... 9
5.4 Processing of verification results ... 12
5.5 Verification cycle ... 13
Annex A Verification records for carbon monoxide and carbon dioxide infrared
gas analyzer... 14
Annex B Inner page format of verification certificate ... 16
Annex C Inner page format of notification of verification results ... 17
Carbon Monoxide and Carbon Dioxide Infrared Gas
Analyzer
1 Scope
This Standard applies to the initial verification, subsequent verification and in-
use inspection of carbon monoxide, carbon dioxide infrared gas analyzer
(hereinafter referred to as the instrument).
2 Overview
The instrument is mainly composed of infrared sensor plus electronic parts and
display part. The sensor converts the detected carbon monoxide gas or carbon
dioxide gas into an electrical signal. And then it is processed by electronic parts.
Display as concentration value.
The instrument can be divided into continuous measurement and discontinuous
measurement instruments according to the working state. According to the
sampling method, it can be divided into diffusion type and suction type
instruments.
3 Metering performance requirements
3.1 Detection gas, indication error, repeatability and response time
See Table 1 for detection gas, indication error, repeatability and response time.
Table 1 -- Detection gas, indication error, repeatability and response time
3.2 Drift
3.2.1 Zero drift: not greater than the instrument's indication value reference
error.
3.2.2 Range drift: not greater than the instrument's indication value reference
error.
3.3 Non-measured component interference error
3.3.1 Interference error of non-measured components excluding water vapor:
±2%FS.
3.3.2 Water vapor interference error: not greater than the instrument's indication
value reference error.
4 General technical requirements
4.1 Appearance
4.1.1 The instrument shall be marked with the name of the manufacturer, the
instrument model and serial number, and the date of manufacture.
Domestically-made instruments must have the mark and number of the
manufacturing license for measuring instruments. The accessories shall be
complete, with instructions for use.
4.1.2 The display of the instrument shall be clear and complete. Each regulator
component shall be able to work normally. The fasteners shall not be loose.
4.1.3 The instrument shall not have appearance damage that affects its normal
operation.
4.2 Insulation resistance
Insulation resistance ≥40MΩ.
4.3 Insulation strength
For instruments that use alternating current, the insulation strength of the phase
(or middle) line of the power supply to the ground shall be able to withstand the
test of which the AC voltage is 1500V, 50Hz and the test current is 10mA, which
lasts for 1min.
5 Measuring instrument control
The measuring instrument control of the instrument includes the initial
verification, subsequent verification and in-use inspection.
5.3 Verification methods
5.3.1 Appearance
Use visual inspection and hand feel method according to requirements of 4.1.
5.3.2 Instrument adjustment
Carry out the warm-up stabilization of the instrument and the adjustment of the
zero point and the indication value according to the requirements of the
instrument manual.
During the instrument verification, connect the standard gas, the flow controller
and the inspected instrument as shown in Figure 1. According to the different
sampling methods of the tested instrument, use the flow controller to control
different standard gas flow. When verifying a diffusion instrument, the flow rate
shall be in accordance with the requirements of the instrument manual. If there
is no clear requirement in the instrument manual, it is generally controlled in the
range of (300±50) mL/min. When verifying suction instruments, it is necessary
to ensure that the bypass flowmeter in the flow controller has flow vent.
5.3.3 Indication value reference error
Access the standard gas with a concentration of approximately 20%, 50% and
80% of the upper limit of the instrument range. After the reading is stable, record
the display value Ai of the instrument. Repeat the measurement 3 times.
Calculate the reference error Δe of the indication value of each concentration
point of the instrument according to formula (1). Take the largest absolute value
Δe as the indication error of the instrument.
Where,
- Arithmetic mean of the values displayed by the instrument at each
concentration test point;
As - Concentration value of standard gas;
R - Upper limit of the measuring range of the instrument (the same below).
5.3.4 Repeatability
Access standard gas with a concentration of about 50% of the upper limit of the
instrument range. After the reading is stable, record the instrument display
value Ai. Then access zero-point gas. After the instrument is stable, access the
standard gas of the above concentration. Repeat the above measurement 6
times. Repeatability is expressed as the relative standard deviation of a single
measurement. Calculate the repeatability sr of the instrument according to
formula (3):
5.3.5 Response time
Access standard gas with a concentration of about 50% of the upper limit of the
instrument range. After the instrument display value stabilizes, record the
instrument reading. Then access zero-point gas. After the instrument is stable,
access the standard gas of the above concentration. At the same time start the
stopwatch to start timing. When the indication value of the instrument reaches
90% of the last stable value, stop the watch, and the time displayed by the
stopwatch shall be the response time. Repeat the measurement 3 times. Take
the arithmetic average value as the response time of the instrument.
5.3.6 Drift
Access zero-point gas. After the instrument is stable, record the displayed value
of the instrument Az0. Access standard gas with a concentration of about 50%
of the upper limit of the instrument range. After the instrument is stable, record
the reading As0. Remove the standard gas. Discontinuity measurement
instrument runs for 1h. Repeat the above steps every 15min. Continuity
measurement instrument runs for 8h. Repeat the above steps every 2h. At the
same time record the instrument display values Azi and Asi (i=1,2,3,4). Calculate
the zero drift Δzi according to formula (5). Take the largest absolute value Δzi as
Figure 2 -- Water vapor generator
5.3.9 Insulation resistance
The instrument is not connected to the power supply, and the power switch is
on. Respectively connect the two wires of the insulation resistance tester to the
phase (or center) wire and ground terminal of the power plug of the instrument.
Use the insulation resistance tester to measure the insulation resistance of the
instrument.
5.3.10 Insulation strength
The instrument is not connected to the power supply, and the power switch is
on. Respectively connect the two wires of the insulation strength tester to the
phase (or center) wire and ground terminal of the power plug of the instrument.
The voltage shall rise steadily to 1500V during the test. Test current is 10mA.
Remain 1min. During the test, the instrument shall not experience breakdown
or arcing.
5.4 Processing of verification results
For qualified instruments verified according to the regulations and requirements
of this Regulation, a verification certificate will be issued, and the qualification
level of the instrument will be indicated. For instruments that fail to pass the
verification, a verification result notification will be issued, and the unqualified
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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