Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the certification, calibration, and metrological services for equipment such as gas alarms, flammable gas detectors, and toxic/hazardous gas detection instruments, serving a variety of locations. With qualifications to serve nationwide, we address various electrical safety and explosion-proof/fire prevention issues for customers, contributing to safe production and operation.
Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for Calibration of Combustible Gas Detectors" (JJG693-2011) states: The calibration cycle for combustible gas detection and alarm instruments: The calibration cycle of the instrument generally should not exceed one year. If there is any doubt about the instrument's measurement data, or if the instrument has been replaced with major components or repaired, it should be sent for calibration promptly.
Section 3.5 of the "Regulations for the Use of Combustible Gas Detection and Alarm Systems" (SY6503-2000) stipulates: Combustible gas detection and alarm systems in use shall be calibrated regularly as required.
Occupational Health Service - Technical Regulations for the Setting of Toxic Gas Facilities (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be carried out regularly in accordance with 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: The flammable gas detectors and alarms installed and used shall have measuring instruments manufactured by an institution recognized for their **measurement** and **explosion-proof** performance.

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 Alarm Meter Calibration Conditions and Requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
Relative humidity: ≤85%.
3. The working environment should not affect the normal operation of the instrument with electromagnetic fields and interfering gases.
Calibration Tools and Instruments
1) Standard Gas Material
The relative expanded uncertainty of the gas standard material does not exceed 2% (k=2).
2) Standard Gas Dilution Unit: Dilution Error of 1%
3) Stopwatch: Graduation not greater than 0.1s.
4) Flow Control: Flow range not less than 500 mL/min, flow grade not less than level 4.
5) Zero Point Gas: Purified compressed air.
6) Pressure Reducing Valve: A pressure reducing valve that matches with the calibrated cylinder.
7) Gas Pipeline: Use gas tubes made of materials like polytetrafluoroethylene or stainless steel that do not affect the concentration of the tested gas.

Verification Method
Appearance and structure
Inspect and feel in accordance with the requirements of 4.1.
Logos and Branding
Proceed as per 4.2 requirements, observed visually.
Power-on inspection
Inspect visually and by touch, as per 4.3 requirements, to check the alarm function and the value of the alarm action in 5.3.4.
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 properly, and record the readings at the time of the alarm. Repeat the measurement three times, with the arithmetic mean of the three readings being the instrument's alarm action value.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is an independent third-party organization providing services such as regular certification, metrology, and calibration for electrical safety, electrical explosion-proofing, gas alarms, and toxic gas detection instruments. We are qualified to address fire and explosion prevention issues for our clients.