Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, certification, and measurement services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment in various locations. We provide services nationwide, addressing clients' electrical safety and explosion-proof fire prevention issues, and contributing to safe production.
Gas Alarm Meters Calibration Conditions and Requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
2. Relative Humidity: ≤85%
3. The working environment should not affect the normal operation of the instrument with electromagnetic fields and interfering gases.
Calibration Tools and Instruments
1) Certified Reference Gases
The relative expanded uncertainty of the gas standard material 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 range not less than 500 mL/min, flow grade not less than level 4.
5) Zero Point Gas: Purified compressed air.
6) Pressure Reducing Valve: A pressure reducing valve that matches with the calibrated cylinder.
7) Gas Pipeline: Tubing made of materials such as polytetrafluoroethylene or stainless steel that do not affect the concentration of the measured gas.

The calibration cycle for flammable gas detectors is typically once a year.
In accordance with the standard JJG 693-2011 "Flammable Gas Detectors," the calibration cycle for flammable gas detectors generally does not exceed one year. This means that under normal circumstances, a comprehensive calibration and testing of the flammable gas detectors is required annually to ensure their performance meets the relevant requirements.

GB 12358-2024 "General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace" is an important standard.
Intended to standardize the performance, functions, and testing methods of environmental gas detection alarm instruments used in workplace operations.
The standard was issued in 1990 and has undergone several revisions.
The new version is GB 12358-2024, which will be officially implemented on June 1, 2025.
This standard applies to the production and use of detection and alarm instruments for combustible gases, toxic and harmful gases, and oxygen in workplaces.

Gas Standard Material
We use gas standard substances of the same type as the measured gas by the instrument, such as methane or ethane, or alternative substances like isopropanol can be used for gas standards. If the instrument does not specify the type of gas being measured, the concentration of the gas at the alarm set point should be approximately 60% of the full scale. The uncertainty of the expanded gas standard substance is not significant (%). The standard gas should not exceed 0.1% in terms of the flow value error of the repetitive dilution device for low concentration gas standard substances. The concentration unit of the dilution device for gas standard substances should be converted to match the units of the tested instrument, and the discrepancy should not exceed 0.1%.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party service provider specializing in electrical safety, electrical explosion prevention, gas alarms, and toxic and harmful gas detection instruments, offering regular inspections, metrological services, and calibrations. We are licensed to assist clients in addressing fire and explosion prevention issues.