Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the certification, calibration, and metrological services for equipment such as gas alarms, combustible gas detectors, and toxic gas analyzers for various locations. We hold qualifications to serve nationwide, providing solutions for all kinds of electrical safety and explosion-proof fire prevention issues, contributing to safe production.
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.

Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for the Verification of Combustible Gas Detectors" (JJG693-2011) stipulates: The verification cycle for combustible gas detection and alarm instruments: The verification cycle of the instrument generally should not exceed one year. Instruments with suspected measurement data, instruments that have replaced major components, or those that have been repaired should be submitted for verification promptly.
Section 3.5 of the "Regulations 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.
Section 7.2.1 of "Code for the Setting of Toxic Gas Equipment in Workplaces" (GBZ/T223-2009) stipulates: Calibration of detection and alarm devices should be carried out regularly according to the manufacturer's specified time and procedures.
Regulation 3.4 of "Code for the Use of Flammable Gas Detectors and Alarms" (SY6503-2000) stipulates: The flammable gas detectors and alarms installed and used should have measurement instruments manufactured by recognized agencies and **explosion-proof performance**.

Calibration Method
Appearance and structure
Inspect and feel according to the requirements of Section 4.1
Logos and Branding
Proceed as per the requirements of Section 4.2 by visual inspection.
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 sound and light alarm functions normally and record the instrument's reading at the time of the alarm. Repeat the measurement three times, and the arithmetic mean of the three readings is the instrument's alarm action value.

Which gas detectors require regular calibration and verification?
Fixed-install, handheld, and portable gas detectors, gas alarm instruments, toxic and harmful gas detectors/alarm systems, flammable gas detectors/alarm systems, gas analyzers, etc.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas detectors, and toxic/hazardous gas alarm instruments for regular inspections, metrological measurements, and calibrations. We hold the necessary qualifications to assist customers in addressing fire and explosion prevention issues.