Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, certification, and metrological services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We provide services nationwide, addressing all sorts of electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
Gas Alarm Meters Calibration Conditions and Requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
Relative Humidity: ≤85%
3. The working environment should not affect the normal operation of the instrument with electromagnetic fields and interfering gases.
Inspection Gauges and Instruments
1) Certified Reference Material for Gases
The relative expanded uncertainty of the gas standard substance does not exceed 2% (k=2).
2) Standard Gas Dilution Device: Dilution error of 1%.
3) Stopwatch: Graduation not greater than 0.1s.
4) Flow Control: Flow rate not less than 500 mL/min, flow grade not lower than 4.
5) Zero Point Gas: Purified compressed air.
6) Pressure Relief Valve: A pressure relief valve that matches the calibrated cylinder.
7) Gas Pipeline: Tubing made of materials like polytetrafluoroethylene or stainless steel, which do not affect the concentration of the tested gas.

Which gas detectors require regular calibration and verification?
Fixed-install, handheld, and portable gas detectors, gas alarm instruments, toxic and harmful gas detectors/alarm systems, flammable gas detectors with alarms, gas analyzers, etc.

Appearance and structure
The instrument should not have any appearance damage that affects its normal operation. The surface of newly manufactured instruments should be smooth and glossy, with a uniform paint and plating layer, free of peeling and rusting.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Logos and Symbols
Instrument name, model, manufacturer's name, date of manufacture, serial number, explosion-proof marking and number, as well as the manufacturing metrological instrument license marking and number for domestic instruments should be clear.

Verification Method
Appearance and structure
Inspect visually and by touch according to the requirements of Section 4.1
Logos and Branding
Proceed as per 4.2 requirements, observed visually.
Power-on inspection
Inspect visually and by touch, in accordance with 4.3 requirements, to check the 5.3.4 alarm function and alarm action values.
Introduce a standard gas substance with a concentration greater than the alarm set point, causing the instrument to trigger an alarm. Observe whether the instrument's sound and light alarm functions normally and record the instrument's reading when the alarm is triggered. Repeat the measurement three times, with the arithmetic mean of the three readings being the instrument's alarm trigger value.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic and harmful gas alarm instruments for regular inspections, metrological services, and calibration. We are licensed to provide solutions for fire and explosion prevention issues for our clients.