Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, certification, and metrological services for equipment such as gas alarms, flammable gas detectors, and toxic/hazardous gas detection instruments for various locations. We provide nationwide services, addressing various electrical safety and explosion-proof/fire prevention issues for our clients, and contributing to safe production.
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 and alarm instruments used in work sites.
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 gas detection and alarm instruments for flammable gases, toxic and harmful gases, and oxygen in workplace environments.

Regular Inspection Content for Gas Detectors
Installation spacing of inspection (probe) points
2. Installation Height of the Detector
3. Indicated Error (Concentration)
4. Repeatability (Concentration)
5. Alarm Error (Concentration)
6. Response Time (Seconds)

Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for Calibration of Combustible Gas Detectors" (JJG693-2011) stipulates: The calibration cycle for combustible gas detection and alarm instruments: The calibration cycle of the instrument generally should not exceed one year. If there is any doubt about the measurement data of the instrument, or if the instrument has been replaced with major components or repaired, it should be sent for calibration promptly.
Section 3.5 of the "Code for the Use of Combustible Gas Detection and Alarm Devices" (SY6503-2000) stipulates: Combustible gas detection and alarm devices in use shall be calibrated regularly as required.
Occupational Health Service Facilities Toxic Gas Equipment Installation Code (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be carried out regularly according to the manufacturer's specified time and procedures.
Section 3.4 of the "Regulations for the Use of Combustible Gas Detectors" (SY6503-2000) stipulates: Combustible gas detectors for installation and use shall have measurement instruments manufactured by an institution recognized for their**explosion-proof performance**.

Calibration Method
Appearance and structure
Inspect visually and by touch according to the requirements of 4.1
Logos and branding
Observe per 4.2 requirements.
Power-on inspection
Inspect visually and by touch according to the requirements of 4.3 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 audio-visual alarm is functioning properly and record the instrument's reading when the alarm is triggered. Repeat the measurement three times, and the arithmetic mean of the three readings is the instrument's alarm action value.
Shenzhen ZhongNuo Inspection & Technology Co., Ltd. is an independent third-party institution specializing in electrical safety, electrical explosion-proof services, periodic verification, measurement, and calibration of gas detectors and toxic gas alarm instruments. We provide资质 to address fire and explosion prevention issues for our clients.