Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment, serving various locations nationwide. We address a range of electrical safety and explosion-proof fire prevention issues for clients, contributing to safe production.
Power-on inspection
After powering on the instrument, it should operate normally with clear and complete display sections. Check the alarm function and alarm set points.
Alarm function and alarm action value verification
The instrument's acoustic and light alarm should be normal. Insulation resistance.
Insulation resistance for instruments using alternating current power should be not less than 20MΩ.

Gas Alarm Meters Calibration Conditions and Requirements
Environmental Conditions
Ambient Temperature: 0~40℃
2. Relative Humidity: ≤85%
3. The working environment should not interfere with the normal operation of the instrument by electromagnetic fields or interfering gases.
Calibration Tools and Instruments
1) Certified Reference Materials 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 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: Tube for gas pipelines, such as polytetrafluoroethylene or stainless steel, that do not affect the concentration of the tested gas.

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 coating, free of peeling and rusting.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Logos and branding
Instrument name, model, manufacturer, production date, serial number, explosion-proof markings and numbers, as well as the manufacturing measurement instrument license marking and number for domestically manufactured instruments should be clear.

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 interval for flammable gas detectors typically does not exceed one year. This means that under normal circumstances, a comprehensive calibration and testing of the flammable gas detectors should be conducted annually to ensure their performance meets the relevant requirements.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas detectors, and toxic and harmful gas alarm instruments for regular inspections, metrological services, and calibrations. We hold the necessary qualifications to help clients address fire and explosion prevention issues.