Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the certification, calibration, and metrological services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment for various locations. We have qualifications to serve nationwide, providing solutions for electrical safety and explosion-proof fire prevention issues, and contributing to safe production.
Measurement Instrument Control
Instrument control includes calibration, follow-up calibration, and in-service inspection.

Regular Inspection Items for Environmental Gas Detection and Alarm Equipment in Workplace Operations:
Alarm sound and light (if applicable)
2. Low response value
3. Indication Error (for Gas Detectors/Gas Detector Alarms)
4. Instrument Drift (in Portable Instruments)
5. Alarm Error (for Gas Detection Alarm/ Gas Alarm)
6. Pump-suction instrument gas collection distance and flow rate (for pump-suction instruments)
7. Power Supply (for battery-powered instruments)
8. Response Time
9. Status Indicator (with Wireless Communication Function)

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 for methane, ethane, or other gases 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 instrument being tested when in use.

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 by electromagnetic fields or interfering gases.
Calibration Tools and Instruments
1) Standard Gas Substance
The relative expanded uncertainty of the gas standard substance 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 like polytetrafluoroethylene or stainless steel that do not affect the concentration of the tested gas.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution providing regular certification, metrological testing, and calibration services for electrical safety, electrical explosion-proofing, gas detectors, and toxic and harmful gas alarm instruments. We hold qualifications to help customers solve fire and explosion prevention issues.