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 in various locations. We hold the necessary qualifications to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention issues, and contributing to safe production.
The instrument's detection principles primarily include 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.

Calibration Method
Appearance and structure
Inspect and feel according to requirements in Section 4.1
Logos and Branding
Inspection shall be conducted in accordance with requirement 4.2 as per sight.
Power-on inspection
Inspect visually and by touch, in accordance with 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 trigger value.

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

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 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 detection and alarm instruments for flammable gases, toxic and harmful gases, and oxygen in workplaces.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is an independent third-party service provider specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic/hazardous gas detection instruments. We offer regular calibration, measurement, and certification services, as well as qualifications to address fire and explosion prevention issues for our clients.