Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services of gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment for various locations. We hold qualifications to serve nationwide, providing solutions to electrical safety and explosion-proof fire prevention issues for clients, and contributing to safe production.
Appearance and structure
The instrument should not have any appearance damage that affects its normal operation. The surface of newly manufactured instruments should be smooth and glossy, with a uniform paint and plating coating, free of peeling or rusting.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Logos and branding
Instrument name, model, manufacturer's name, date of manufacture, serial number, explosion-proof marking and number, as well as the manufacturing metrological instrument license marking and number for domestic instruments should be clear.

Power-on inspection
The instrument should operate normally after being powered on, with the display sections being clear and complete. Check the alarm function and the alarm action values.
Alarm function and alarm action value verification
The instrument's sound and light alarm should be functioning normally. Insulation resistance
Insulation resistance for instruments using AC power should not be less than 20MΩ.

Regulatory Testing and Methods for Combustible Gas Detectors
Annually, we conduct annual inspections on industrial and commercial alarm sensor probes to ensure their accuracy, repeatability, hysteresis, and response time meet the standards. Additionally, we check the suitability of the alarm sensor's installation location and whether it is affected by interference from other equipment.

Standard for verification and metrological calibration of combustible and toxic harmful gas alarms:
GB/T 50493-2019 "Design Standard for Detection and Alarm 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规程 for Inspection and Calibration of Combustible Gas Detectors
Shenzhen ZhongNuo Testing Technology Co., Ltd. is an independent third-party organization providing regular certification, measurement, and calibration services for electrical safety, electrical explosion-proof equipment, gas detectors, and toxic and harmful gas alarm instruments. We are qualified to assist clients in addressing fire and explosion prevention issues.