Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in calibration, calibration, and metrological services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment in various facilities. We hold qualifications to serve nationwide, providing solutions for electrical safety and explosion-proof fire prevention issues, contributing to safe production and operation.
GB 12358-2024 "General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplaces" is an important standard.
Intended to standardize the performance, functions, and testing methods of environmental gas detection and alarm instruments used in workplace operations.
The standard was published 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 gas detection and alarm instruments for flammable gases, toxic and harmful gases, and oxygen in work environments.

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 even paint and coating, free of peeling and rusting.
The instrument's connections are reliable; all dials or buttons should operate and control normally.
Logos and trademarks
Instrument name, model, manufacturer's name, production date, serial number, explosion-proof mark and number, as well as the manufacturing metrological instrument license mark and number of domestically manufactured instruments, should be clear.

Regular inspection contents for gas alarms
Installation spacing of inspection (detection) points
2. Installation Height of the Detector
3. Indicated Error (Concentration)
4. Repeatability (Concentration)
5. Alarm Error (Concentration)
6. Response Time (Seconds)

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 Materials for Gases
The relative expanded uncertainty of the gas standard substance 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 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 that do not affect the concentration of the tested gas, such as polytetrafluoroethylene or stainless steel pipes.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proof, gas alarm, and toxic gas detection instrument calibration, metrological testing, and regular certification services. We provide qualifications to help clients solve fire and explosion prevention issues.