Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the certification, calibration, and metrological services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment in various locations. We are licensed to serve nationwide, providing solutions for electrical safety and explosion-proof fire prevention issues to facilitate 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 due to electromagnetic fields and interfering gases.
Calibration Tools and Instruments
1) Standard Gas Substance
The relative expanded uncertainty of the gas standard material does not exceed 2% (k=2).
2) Standard Gas Dilution Unit: 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 Reducing Valve: A pressure reducing valve that matches with the calibrated cylinder.
7) Gas Pipeline: Tube for gas pipelines, such as polyethylene or stainless steel, that do not affect the concentration of the measured gas.

Power-on inspection
After power is applied to the instrument, it should operate normally with clear and complete display. Check the alarm function and the alarm action values.
Alarm function and alarm action value check
The instrument's acoustic and light alarm should be functioning normally. Insulation resistance
Insulation resistance for instruments using AC power should be not less than 20MΩ.

Gas Standard Material
The gas standard substance used should be of the same type as the gas measured by the instrument, such as methane or other gases; alternative substances like isopropanol can also be used. If the instrument does not specify the type of gas being measured, the concentration of the gas at the 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 have an error in the flow indication of the repeatability dilution device greater than 0.1%. The concentration unit of the gas standard substance should be converted to match the unit of the inspected instrument when in use, and the discrepancy should not exceed 0.1%.

Measurement Equipment Control
Instrument control encompasses calibration, subsequent calibration, and in-use inspection.
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, providing regular verification, measurement, and calibration services. We hold the necessary qualifications to assist clients in addressing fire and explosion prevention issues.