Shenzhen ZhongNuo Inspection & Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, flammable gas detectors, toxic gas monitors, and other equipment at various locations. We hold the necessary qualifications to serve customers nationwide, addressing a range of electrical safety and explosion-proof fire prevention issues, and contributing to safe production.
Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for Verification of Combustible Gas Detectors" (JJG693-2011) states: The verification cycle for combustible gas detection and alarm instruments: Generally, the verification cycle of the instrument should not exceed one year. If there is any suspicion about the measurement data of the instrument, or if the instrument has been replaced with major components or repaired, it should be sent for verification promptly.
Section 3.5 of the "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 Station Toxic Gas Equipment Installation Specification (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 Combustible Gas Detectors" (SY6503-2000) stipulates: Combustible gas detectors for installation and use shall have measurement instruments manufactured by an institution recognized for their**explosion-proof performance**.

Calibration Method
Appearance and structure
Inspect and feel in accordance with the requirements of 4.1
Branding and Logos
Inspect as per 4.2 requirements.
Power-on inspection
Inspect visually and by touch, in accordance with 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 sound and light alarm functions properly and record the instrument's reading at the time of the alarm. Repeat the measurement three times, with the arithmetic mean of the three readings being the instrument's alarm trigger value.

Appearance and structure
The instrument should not have any appearance damage that affects its normal operation. The surface of newly manufactured instruments should be smooth and even, with a uniform paint and coating, free of peeling and rusting.
The instrument's connections are reliable, and all knobs or buttons should operate and control normally.
Logos and trademarks
Instrument name, model, manufacturer's name, date of manufacture, serial number, explosion-proof marking and number, as well as the manufacturing measurement instrument license marking and number for domestic instruments should be clear.

Regular Inspection Content and Methods for Combustible Gas Detectors
Annual inspections of industrial and commercial alarm sensors are conducted regularly, primarily checking for the accuracy error, repeatability, drift, and response time of the alarms to ensure compliance with standards. Additionally, the suitability of the alarm installation location and any interference from other equipment are inspected.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic and harmful gas alarm instruments for regular inspections, metrological measurements, and calibrations. We hold the necessary qualifications to assist clients in addressing fire and explosion prevention issues.