Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the certification, calibration, and metrological services for equipment such as gas alarms, combustible gas detectors, and toxic and harmful gas detectors for various locations. We are licensed to serve nationwide, providing solutions for electrical safety and explosion-proof fire prevention issues to facilitate safe production.
Standard for verification and calibration of combustible and toxic gas detectors:
GB/T50493-2019 "Design Standard for Detection and Alarm of 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"

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 due to electromagnetic fields and interfering gases.
Inspection Gauges 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 Relief Valve: A pressure relief valve that matches with the calibrated cylinder.
7) Gas Pipeline: Tubing made of materials like polyethylene or stainless steel, which do not affect the concentration of the gas being measured.

What factors can influence the calibration cycle of a combustible gas detector?
Manufacturer Requirements: Different manufacturers may have varying inspection cycle requirements for their flammable gas detectors. Therefore, when purchasing equipment, carefully review the product manual to understand the specific requirements of the manufacturer.
Equipment Operating Environment: The operating environment of the alarm directly affects its inspection cycle. If the equipment is frequently exposed to high concentrations of harmful gases, high or low humidity, or high or low temperatures for extended periods, its inspection cycle may be accordingly shortened.
‌Equipment Maintenance Status: The condition of equipment maintenance is also a significant factor affecting the inspection cycle. If the equipment faces issues like battery depletion and sensor aging over a long period, the inspection cycle will accordingly be shortened.

Regular Inspection Items for Environmental Gas Detection and Alarm Equipment at Workplaces:
1. Alarm sound and light (if applicable)
2. Low response value
3. Indicated Error (for Gas Detectors/ Gas Detector Alarms)
4. Instrument Drift (in portable instruments)
5. Alarm Error (for Gas Detection Alarm/ Gas Alarm)
6. Pump-actuated instrument gas collection distance and flow rate (for pump-actuated instruments)
7. Power Supply (for battery-powered instruments)
8. Response Time
9. Status Indicator (with wireless communication function)
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 equipment for regular calibration, metrological testing, and certification services, offering qualifications to address fire and explosion prevention issues for clients.