Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the certification, calibration, and measurement services for equipment such as gas alarms, flammable gas detectors, and toxic/hazardous gas detection instruments for various locations. We are qualified to serve nationwide, providing solutions to electrical safety and explosion-proof fire prevention issues for clients, facilitating safe production.
Standard for verification and metrological calibration of combustible and toxic gas detectors:
GB/T50493-2019 Standard for Design of Detection and Alarm Systems for Combustible and Toxic Gases in Petroleum and Chemical Industries
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace
JJG693-2011 "Regulation for Calibration of Combustible Gas Detectors"

The detection principle of the instruments mainly includes catalytic combustion, infrared absorption, and thermal conductivity types. The sampling methods include diffusion and aspiration. The instruments are primarily composed of detection elements, amplification circuits, alarm systems, and displays, used for monitoring the concentration of combustible gases in the environment.

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

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 clean, with a uniform paint and coating, free of peeling and rusting.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Logos and branding
Instrument name, model, manufacturer, 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.
Shenzhen ZhongNuo Inspection & Testing Technology Co., Ltd. is an independent third-party organization specializing in electrical safety, electrical explosion-proof, gas alarm, and toxic gas detection instrument calibration, metrological verification, and regular inspections. We provide qualification services to address fire and explosion prevention issues for our clients.