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.
Power-on inspection
The instrument should operate normally after being powered on, with clear and complete display. Check the alarm function and the alarm action values.
Alarm function and alarm action value verification
The instrument's sound and light alarm should function normally. Insulation resistance.
Insulation resistance for equipment using AC power should be no less than 20MΩ.

Regular Inspection Items for Environmental Gas Detection and Alarm Equipment in Workplace Operations:
Alarm sound and light (if applicable)
2. Small response value
3. Indication Error (for Gas Detectors/Gas Detector Alarms)
4. Instrument Drift (in Portable Instruments)
5. Alarm Error (for Gas Detector/ 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)

Gas Alarm Meters 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.
Calibration Tools and Instruments
1) Gas Standard Material
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: Graduation not greater than 0.1s.
4) Flow Control: Flow rate 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: Tubing made of materials such as polytetrafluoroethylene or stainless steel that do not affect the concentration of the gas being tested.

The detection principle of the instruments primarily includes catalytic combustion, infrared absorption, and thermal conductivity types. The sampling methods are diffusion and aspiration. The instruments are mainly composed of detection elements, amplification circuits, alarm systems, and displays, used for monitoring the concentration of combustible gases in the environment.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proof, gas alarm, and toxic and harmful gas alarm instrument calibration, regular inspections, and metrological services, providing qualifications to clients for fire and explosion prevention solutions.