Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and metrological services for gas alarms, combustible gas detectors, and toxic gas detectors for various locations. We hold qualifications to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention issues, contributing to safe production.
Which gas detectors require regular calibration and verification?
All types of in-use fixed installation, handheld, portable gas detectors, gas alarm instruments, toxic and harmful gas detectors/alarm systems, flammable gas detectors with alarms, gas analyzers, etc.

Gas Standard Material
The gas standard substance used should be of the same type as the gas measured by the instrument, such as methane, ethane, or other gases; for example, isobutanol can be used for gas standards. If the instrument does not specify the type of gas being measured, the concentration of the gas at the set point for methane, ethane, and 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 indicating unit of the tested instrument when in use.

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

Verification Method
Appearance and structure
Inspect visually and by touch according to the requirements of 4.1
Logos and Branding
Inspect as per requirement 4.2.
Power-on inspection
Inspect visually and by touch, in accordance with 4.3 requirements, to check the 5.3.4 alarm function and alarm action values.
Introduce a standard gas substance with a concentration greater than the alarm set point, causing the instrument to trigger an alarm. Observe if the instrument's sound and light alarm is functioning properly and record the reading at the time of the alarm. Repeat the measurement three times, and the arithmetic mean of the three readings is the instrument's alarm trigger value.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic and harmful gas alarm instruments for regular inspections, metrological measurements, and calibrations. We are qualified to address fire and explosion prevention issues for our clients.