Shenzhen ZhongNuo Inspection Technology Co., Ltd. specializes in the certification, calibration, and metrological services for gas alarms, combustible gas detectors, and toxic gas detection instruments for various locations. We are fully qualified to serve nationwide, addressing electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
Gas Standard Material
We use gas standard substances of the same type as the gas measured by the instrument, such as methane or gas standards, which can also be isopropanol, etc. If the instrument does not specify the type of gas being measured, the concentration of the gas with a 60% span setting is approximately the full-scale of the standard substance. The uncertainty of the expanded gas standard substances is not significant (%). The flow indication error of the repetitive dilution device should not be greater than 0.1% for gas standard substances with high concentrations. The concentration unit of the dilution device for gas standard substances should be converted to match the unit of the inspected instrument. The uncertainty should not exceed 0.1%.

Regulatory Content and Methods for Regular Inspection of Flammable Gas Detectors
Annually, we conduct annual inspections 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, we verify the suitability of the alarm installation locations and check for any interference from other equipment.

What factors affect the calibration cycle of flammable gas detectors?
Manufacturer Requirements: Flammable gas detectors from different manufacturers may have varying inspection cycle requirements. Therefore, when purchasing equipment, carefully review the product manual to understand the specific requirements of the manufacturer.
Equipment Operating Environment: The operating environment of the alarm directly affects its inspection cycle. If the equipment is exposed to high concentrations of harmful gases, high humidity, or extreme temperatures (either high or low) for extended periods, the inspection cycle may be shortened accordingly.
‌Equipment Maintenance Status: The condition of equipment maintenance is also a significant factor affecting the inspection cycle. If the equipment faces issues like battery depletion or sensor aging over a long period, the inspection cycle will accordingly be shortened.

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 re-calibration process, if there are any doubts about the instrument's test data, or if the main components of the instrument are replaced, or if recalibration is required after repairs.
Shenzhen Zhongnuo Inspection Technology Co., Ltd. is a third-party institution that offers regular certification, measurement, and calibration services for electrical safety, electrical explosion-proofing, gas alarms, and toxic/hazardous gas detection instruments, and is qualified to assist clients in addressing fire and explosion prevention issues.