Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We hold qualifications to serve nationwide, addressing electrical safety and explosion-proof fire prevention issues for clients, and contributing to safe production.
Flammable and toxic/hazardous gas detectors verification and calibration according to standards:
GB/T50493-2019 "Design Standard for Detection and Alarm Systems of Combustible Gases and Toxic Gases in Petroleum and Chemical Industries"
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace
JJG 693-2011 "Regulation for Calibration of Combustible Gas Detectors"

Regular Inspection Items for Environmental Gas Detection and Alarm Equipment in Workplace Operations:
1. Alarm sound and light (if applicable)
2. Small response values
3. Indicating 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 capability)

The calibration cycle for flammable gas detectors is typically once a year.
According to the standard JJG 693-2011 "Flammable Gas Detectors," the calibration cycle for flammable gas alarms generally does not exceed 1 year. This means that, under normal circumstances, a comprehensive calibration and testing of the flammable gas alarms should be conducted annually to ensure their performance meets the relevant requirements.

Gaseous 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 Gas Standards
The relative expanded uncertainty of the gas standard material does not exceed 2% (k=2).
2) Standard Gas Dilution Device: 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 Reducing Valve: A pressure reducing valve that is compatible with the calibrated cylinder.
7) Gas Pipeline: Use气管, such as polytetrafluoroethylene or stainless steel pipe, that does not affect the concentration of the measured gas.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution that provides regular certification, metrology, and calibration services for electrical safety, electrical explosion-proofing, gas alarms, and toxic/hazardous gas detection instruments, and helps customers address fire and explosion prevention issues.