Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, verification, and metrological services for gas alarms, combustible gas detectors, and toxic gas detection instruments for various locations. We hold qualifications to serve nationwide, providing solutions for electrical safety and explosion-proof fire prevention issues, facilitating safe production.
Gas Standard Material
We use gas standard substances with the same type of gas as the one measured by the instrument, such as methane, ethane, or gases like isopropanol. If the instrument does not specify the type of gas being measured, the concentration of the gas at the set point should be about 60% of the full scale for the standard gas. The uncertainty of the expanded gas standard substance is not more than % (the expanded uncertainty of the gas standard substance should be greater than ±1%). The flow indication error of the repetitive dilution device should not be greater than 0.%. The concentration units of the dilution gas standard substance should be converted to match the units of the instrument being tested during use, and should not exceed 0.%.
The detection principle of the instruments primarily includes catalytic combustion, infrared absorption, and thermal conductivity types. The sampling methods are diffusion and aspiration. The instruments are mainly composed of detection elements, amplification circuits, alarm systems, and displays, used for monitoring the concentration of combustible gases in the environment.
How often should various gas detectors be calibrated and tested?
Instrument recalibration is typically every 1 year, determined by the submitting unit based on actual usage. During the secondary calibration process, if there are doubts about the instrument's test data, or if the main components of the instrument are replaced, or if recalibration is needed after repairs.
Regulatory contents and methods for periodic inspections of flammable gas detectors
Annual inspections are conducted on industrial and commercial alarm sensors, primarily checking for the accuracy, repeatability, drift, and response time of the alarms to ensure they meet standards. Additionally, the suitability of the alarm's installation location and any interference from other equipment are assessed.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proof, gas detectors, and toxic and harmful gas alarm instrument calibration, metrology, and periodic verification services. We provide资质 to address fire and explosion prevention issues for our clients.




































