Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, certification, and measurement services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment for various locations. We serve nationwide, addressing all types of electrical safety and explosion-proof fire prevention issues for clients, and contributing to safe production.
Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for Calibration of Combustible Gas Detectors" (JJG693-2011) stipulates: The calibration cycle for combustible gas detection and alarm instruments: Generally, the calibration cycle of the instrument 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: The combustible gas detection and alarm systems in use shall be calibrated regularly as required.
Occupational Health Services - Technical Regulations (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be conducted regularly according to the manufacturer's specified time and procedures.
Section 3.4 of the "Regulation for the Use of Combustible Gas Detectors and Alarms" (SY6503-2000) stipulates that the installation and use of combustible gas detection and alarm devices should have measurement instruments manufactured by an institutionally recognized manufacturer, with explosion-proof performance.

Gas Standard Material
We use gas standard substances of the same type as the gas measured by the instrument, such as methane or ethane, or alternative substances like isopropanol can be used. If the instrument does not specify the type of gas being measured, the concentration of the gas at the set point is approximately 60% of the full scale. The uncertainty of the expanded gas standard substance is not more than % (k-body standard substance greater than ±1%). The flow indication error of the repetitive dilution device should not be greater than 0.%. The concentration unit of the gas standard substance should be converted to match the unit of the inspected instrument during use, and the discrepancy should not exceed 0.%.

Gas alarm meter calibration conditions and requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
2. Relative Humidity: ≤85%
3. The working environment should not affect the normal operation of the instrument with electromagnetic fields and interfering gases.
Inspection gauges and instruments
1) Standard Gas Substance
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: Resolution 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 Relief Valve: A pressure relief valve that is compatible with the calibrated cylinder.
7) Gas Pipeline: Tubing made of materials like polytetrafluoroethylene or stainless steel, which do not affect the concentration of the measured gas.

Standard for verification and calibration of combustible and toxic gas detectors:
Standard GB/T50493-2019 for Design of Detection and Alarm Systems for Combustible Gases and Toxic Gases in Petroleum and Chemical Industry
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace
JJG693-2011 "Regulation for Calibration of Combustible Gas Detectors"
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic/hazardous gas detection instruments, offering regular inspections, metrological measurements, and calibration services. We hold the necessary qualifications to assist clients in solving fire and explosion prevention issues.