Shenzhen ZhongNuo Inspection & 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 in various locations. We hold the necessary qualifications to serve nationwide, addressing electrical safety and explosion-proof fire prevention issues for clients, and contributing to safe production.
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 other gases 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, such as methane, ethane, or isopropanol, is approximately 60% of the full scale. The uncertainty of the expanded gas standard substance is not more than % (the uncertainty of the gas standard substance is greater than ±1%). The flow indication error of the repetitive dilution device should not be higher than the concentration of the gas standard substance. When using the concentration unit of the dilution device for gas standard substances, it should be converted to match the unit of the instrument being tested, and the discrepancy should not exceed 0.%.

Appearance and structure
The instrument should not have any surface damage that affects its normal operation. The surface of newly manufactured instruments should be smooth and even, with a uniform paint and plating coating, free of peeling and rusting.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Branding and Logos
Instrument name, model, manufacturer's name, production date, serial number, explosion-proof marking and number, as well as the manufacturing metrological instrument license mark and number for domestically produced instruments should be clear.

Gas Alarm Detector Regular Inspection Content
Installation spacing of inspection (testing) points
2. Installation Height of the Detector
3. Indicated Error (Concentration)
4. Repeatability (Concentration)
5. Alarm Error (Concentration)
6. Response Time (seconds)

Regular Inspection Items for Environmental Gas Detection and Alarm Instruments in Workplace Operations:
Alarm sound and light (if applicable)
2. Small response values
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-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)
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution that specializes in electrical safety, electrical explosion-proof services, including regular certification, metrological verification, and calibration of gas detectors and toxic gas alarm instruments. We provide qualifications to help customers address fire and explosion prevention issues.