Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, combustible gas detectors, and toxic gas detection instruments at various locations. We hold the necessary qualifications to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention concerns, and contributing to safe production.
Gas alarm meter calibration conditions and requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
2. Relative Humidity: ≤85%
3. The working environment should not interfere with the normal operation of the instrument by electromagnetic fields or interfere gases.
Calibration Tools and Instruments
1) Standard Gas Substance
The relative expanded uncertainty of the gas standard material does not exceed 2% (k=2).
2) Standard Gas Dilution Device: Dilution error of 1%.
3) Stopwatch: Graduation not greater than 0.1s.
4) Flow Control: Flow range not less than 500 mL/min, flow grade not less than level 4.
5) Zero Point Gas: Purified compressed air.
6) Pressure Reducing Valve: A pressure reducing valve that matches with the calibrated cylinder.
7) Gas Pipeline: Tube for gas piping, such as polytetrafluoroethylene or stainless steel pipe, that does not affect the concentration of the tested gas.

Appearance and structure
The instrument should not have any surface damage that affects its normal operation. The surface of newly manufactured instruments should be smooth and glossy, with even paint and plating coatings, and no signs of peeling or rust.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Logos and branding
Instrument name, model, manufacturer's name, production date, serial number, explosion-proof markings and numbers, as well as the manufacturing metrological instrument license mark and number for domestic instruments should be clear.

Regulatory Contents and Methods for Regular Testing of Combustible Gas Detectors
Annual inspections are conducted on the sensors of commercial and industrial alarm systems, primarily checking for the accuracy, repeatability, drift, and response time of the alarms to ensure they meet standards. Additionally, the suitability of the alarm installation location and any interference from other equipment are assessed.

How often should various gas detectors be calibrated and inspected?
Instrument recalibration is typically every 1 year, determined by the sending unit based on actual usage. During the re-certification process, if there are questions about the instrument's test data, or if the main components of the instrument are replaced, as well as after repairs, recalibration is required.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic gas detection instruments, offering regular inspections, metrological measurements, and calibration services. We are qualified to help customers solve fire and explosion prevention issues.