Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We hold the necessary qualifications to serve nationwide, addressing clients' 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 the Verification of Combustible Gas Detectors" (JJG693-2011) states: The verification cycle for combustible gas detection and alarm instruments: Generally, the verification cycle for the instrument should not exceed one year. Instruments with suspected measurement data, instruments that have replaced major components, or those repaired should be promptly submitted for verification.
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.
The "Regulations for the Installation of Toxic Gas Devices in Workplaces" (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be performed 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 authorized body and **explosion-proof performance**.

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 clean, with a uniform paint and coating, free of peeling and rusting.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Logos and brand identifiers
Instrument name, model, manufacturer's name, manufacturing date, serial number, explosion-proof marking and number, as well as the manufacturing measurement instrument license marking and number for domestic instruments should be clear.

Gas Alarm Meters Calibration Conditions and Requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
2. Relative Humidity: ≤85%
3. The working environment should not interfere with the normal operation of the instrument through electromagnetic fields and disturbing gases.
Calibration Tools and Instruments
1) Certified Reference Materials for Gases
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 is compatible with the calibrated cylinder.
7) Gas Pipeline: Tube for gas piping, such as polyethylene or stainless steel, that does not affect the concentration of the tested gas.

Measurement Equipment Control
Instrument control includes calibration, subsequent calibration, and in-use inspections.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is an independent third-party organization providing services such as regular inspection, calibration, and measurement for electrical safety, explosion-proof electrical equipment, gas alarms, and toxic gas detection instruments, helping clients address fire and explosion prevention issues.