Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the certification, calibration, and metrological services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment in various locations. We provide services nationwide, addressing all kinds of electrical safety and explosion-proof fire prevention issues for customers, and promoting 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 ethane, or 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 set point (e.g., 60% of the full scale) is approximately the concentration of the standard substance. The uncertainty of the expanded gas standard substance is not significant (%). The flow rate indication error of the repetitive dilution device should not be greater than 0.1% for high concentration gas standard substances. The concentration unit of the dilution device for gas standard substances should be converted to match the unit of the instrument being tested, and the discrepancy should not exceed 0.1%.

Regulatory contents and methods for periodic inspections of flammable gas detectors
Annual inspections of industrial and commercial alarm sensors are conducted regularly, primarily to check for accuracy errors, 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 also assessed.

Gaseous Detector Alarm Calibrator Specification Requirements
Regulation 5.5 of the "Regulation for Calibration of Combustible Gas Detectors" (JJG693-2011) stipulates: The calibration cycle for combustible gas detection and alarm instruments: The calibration cycle of the instrument generally should not exceed one year. If there is any doubt about the measurement data of the instrument, or if the instrument has been replaced with major components or repaired, it should be sent for calibration promptly.
Section 3.5 of the "Regulations for the Use of Combustible Gas Detection and Alarm Systems" (SY6503-2000) stipulates: The combustible gas detection and alarm systems in use shall be calibrated regularly as per the regulations.
Occupational Health Services - Code for the Installation of Toxic Gas Devices (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices should be conducted regularly according to the manufacturer's specified time and procedures.
Section 3.4 of the "Regulations for the Use of Flammable Gas Detectors and Alarms" (SY6503-2000) stipulates that flammable gas detectors and alarms installed and used should have measurement instruments manufactured by recognized institutions with **excellent explosion-proof performance**.

Gas Alarm Meters 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 and interfering gases.
Calibration Tools and Instruments
1) Certified Reference Materials for Gases
The relative expanded uncertainty of the gas standard material does not exceed 2% (k=2).
2) Standard Gas Dilution Unit: Dilution error of 1%.
3) Stopwatch: graduation not greater than 0.1s.
4) Flow Control: Flow rate 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: Tubing made of materials like polytetrafluoroethylene or stainless steel that do not affect the concentration of the tested gas.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution that specializes in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic and harmful gas alarm instruments for regular inspections, metrological measurements, and calibration services. We are qualified to solve fire and explosion prevention issues for our clients.