Shenzhen Zhongnuo Inspection Technology Co., Ltd. specializes in the certification, calibration, and metrological services for equipment such as gas detectors, combustible gas detectors, and toxic and harmful gas detectors for various locations. We are fully qualified to serve customers nationwide, addressing all sorts of electrical safety and explosion-proof fire prevention issues, and contributing to safe production.
Gas Detector Alarm Calibration Standard Requirements
Regulation 5.5 of the "Regulation for Inspection and Verification of Combustible Gas Detectors" (JJG693-2011) stipulates: The inspection period for combustible gas detection and alarm instruments: Generally, the inspection period for the instrument should not exceed one year. Instruments with suspected measurement data, instruments that have replaced major components, or those repaired should be submitted for inspection promptly.
Section 3.5 of "Regulations for the Use of Combustible Gas Detection and Alarm Systems" (SY6503-2000) stipulates: The combustible gas detection and alarm systems in use shall be calibrated regularly as per the regulations.
Occupational Health Service Establishment Code for Toxic Gas Equipment (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 Flammable Gas Detectors and Alarms" (SY6503-2000) stipulates: Flammable gas detectors and alarms for installation and use shall have measurement instruments manufactured by an institution recognized for their**measurement accuracy** and **explosion-proof performance**.

Regulatory Content and Methods for Regular Inspection of Combustible Gas Detectors
Annual inspections of industrial and commercial alarm sensors are conducted regularly, primarily checking for the accuracy, 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 examined.

Power-on inspection
After power on, the instrument should operate normally and the display should be clear and complete. Check the alarm function and alarm trigger values.
Alarm function and alarm action value verification
The instrument's acoustic and visual alarm should be functioning normally. Insulation resistance.
Insulation resistance for instruments using AC power should be no less than 20MΩ.

Verification Method
Appearance and structure
Inspect visually and by touch according to the requirements of 4.1
Branding and Logos
Inspection to be conducted in accordance with requirement 4.2 by visual means.
Power-on inspection
Inspect visually and by touch, in accordance with the 4.3 requirements, 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 at the time of the alarm. Repeat the measurement three times; the arithmetic mean of the three readings is the instrument's alarm trigger value.
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 services, and calibrations. We hold the necessary qualifications to address fire and explosion prevention issues for our clients.