Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and metrological services for gas alarms, flammable gas detectors, and harmful gas detectors at various locations. We hold qualifications to serve nationwide, addressing electrical safety and explosion-proof fire prevention issues for clients, and contributing to safe production.
Method of Verification
Appearance and structure
Inspect visually and by feel according to the requirements of Section 4.1
Logos and Branding
Inspect in accordance with the requirements of 4.2 by visual means.
Power-on Inspection
Inspect visually and by touch, checking the alarm function and alarm action values in accordance with requirements 4.3 as per 5.3.4.
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 sound and light alarms are functioning properly and record the instrument's readings when the alarm is triggered. Repeat the measurement three times, and the arithmetic mean of the three readings is the instrument's alarm activation value.

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场所.
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 work places.

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 cycle for flammable gas alarms generally does not exceed one year. This means that under normal circumstances, a comprehensive calibration and testing of the flammable gas alarm is required annually to ensure its performance meets the relevant requirements.

The principle of instrument detection mainly includes catalytic combustion, infrared absorption, and thermal conductivity types. Sampling methods include diffusion and aspiration. The instrument is mainly composed of detection elements, amplification circuits, alarm systems, and displays, used for monitoring the concentration of combustible gases in the environment.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas detectors, and toxic gas alarm instruments for regular inspections, metrological measurements, and calibration services. We hold the necessary qualifications to assist clients in solving fire and explosion prevention issues.