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 detectors for various locations. We hold qualifications to serve nationwide, addressing electrical safety and explosion-proof fire prevention issues for clients, and contributing to safe production.
Power-on inspection
The instrument should operate normally and display parts should be clear and complete after being powered on. Check the alarm function and alarm trigger values.
Alarm function and alarm action value verification
The instrument's acoustic and visual alarm should be functioning normally. Insulation resistance
Insulation resistance for instruments using alternating current power should not be less than 20MΩ.

Gas Standard Material
The gas standard substance used should be of the same type as the gas measured by the instrument, such as methane or other gases; gas standards can also use isopropanol, etc. If the instrument does not specify the type of gas being measured, the concentration of the gas at the alarm set point is approximately 60% of the full scale. The uncertainty of the expanded gas standard substance is not large (%). The standard gas concentration for the dilution device should not be greater than 0.1% of the body standard substance. The flow indication error of the dilution device should not be greater than 1% for the repeatability of the dilution device. The concentration unit of the gas standard substance should be converted to match the indicating unit of the inspected instrument. The uncertainty of the gas standard substance should not be greater than 0.1%.

Regulatory Content and Methods for Regular Detection of Flammable Gas Detectors
Annually, we conduct annual inspections on the sensors of commercial and industrial alarm systems, primarily checking for accuracy errors, repeatability, drift, and response time to ensure they meet standards. Additionally, we verify the suitability of the alarm system's installation location and whether it is subject to interference from other equipment.

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 period 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.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proof, gas alarm, and toxic/hazardous gas alarm equipment calibration, regular inspection, and metrological services. We provide资质 to address fire and explosion prevention issues for our clients.