Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the certification, calibration, and metrological services for equipment such as gas alarms, combustible gas detectors, and toxic gas analyzers in various locations. With qualifications to serve nationwide, we provide solutions for electrical safety and explosion-proof fire prevention issues, supporting safe production.
Standard for calibration and verification of combustible and toxic gas detectors:
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 "Regulation for Verification of Combustible Gas Detectors"

Calibration Method
Appearance and structure
Inspect visually and by feel according to the requirements of Section 4.1
Logos and branding
Follow the 4.2 requirements as observed visually.
Power-on inspection
Inspect visually and by touch according to the requirements of 4.3 to check the 5.3.4 alarm function and alarm action values.
Introduce a standard substance of gas with a concentration higher than the alarm setting point, causing the instrument to trigger an alarm. Observe whether the instrument's sound and light alarms are functioning properly, and record the readings at the time of the alarm. Repeat the measurement three times; the arithmetic average of the three measurements is the instrument's alarm trigger value.

The calibration cycle for flammable gas detectors is typically once a year.
In accordance with the standard JJG 693-2011 "Flammable Gas Detectors," the calibration cycle for flammable gas detectors generally does not exceed one year. This means that under normal circumstances, a comprehensive calibration and testing of the flammable gas detectors should be conducted annually to ensure their performance meets the relevant requirements.

How often should various gas detectors be calibrated and tested?
Instrument recalibration is typically every 1 year, determined by the sending unit based on actual usage. During the secondary calibration process, if there are doubts about the instrument test data, or if the main components of the instrument are replaced, or if recalibration is needed after repairs.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party service provider specializing in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic and harmful gas detection instruments for regular calibration, measurement, and verification. We hold the necessary qualifications to assist clients in addressing fire and explosion prevention issues.