Shenzhen ZhongNuo Inspection 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 hold the qualifications to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention concerns, and contributing to safe production.
Regulatory Content and Methods for Routine Detection of Flammable Gas Detectors
Annual inspections of industrial and commercial alarm sensor probes are conducted regularly, primarily to check for the accuracy error, repeatability, drift, and response time of the alarms to ensure they meet standards. Additionally, the suitability of the alarm installation location and any interference from other equipment are also checked.

Verification Method
Appearance and structure
Inspect visually and by touch according to the requirements of 4.1
Branding and logos
Inspect as per requirement 4.2.
Power-on Inspection
Inspect visually and by touch, checking the alarm function and alarm action values according to the requirements of 4.3.
Introduce a standard gas substance with a concentration exceeding the alarm set point, causing the instrument to trigger an alarm. Observe whether the instrument's audio-visual alarm is functioning normally and record the instrument's reading when the alarm is triggered. Repeat the measurement three times, with the arithmetic mean of the three readings being the instrument's alarm trigger value.

How often should various gas detectors be calibrated and tested?
Instrument recalibration is typically every 1 year, determined by the submitting unit based on actual usage. During the secondary calibration process, if there are doubts about the instrument's test data, or if the main components of the instrument are replaced, as well as after repairs, a recalibration is required.

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 work sites.
The standard was issued in 1990 and has undergone multiple 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 workplace environments.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic gas detection instruments, providing regular inspections, metrological measurements, and calibration services. We are qualified to address fire and explosion prevention issues for our clients.