Yangzhou Gas Detector Calibration Institution - ZhongNuo Inspection

Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, verification, and metrological services for equipment such as gas alarms, combustible gas detectors, and toxic gas analyzers in various locations. We hold qualifications to serve nationwide, providing solutions for electrical safety and explosion-proof fire prevention issues, and promoting safe production.
What factors affect the calibration cycle of flammable gas detectors?
Manufacturer Requirements: Different manufacturers may have varying inspection cycle requirements for their flammable gas detectors. 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 frequently exposed to high concentrations of harmful gases, high or low humidity, or extreme temperatures, its 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.

Primary Technical Requirements for Periodic Inspection of Flammable Gas Detectors (Shenzhen ZhongNuo Inspection Technology Co., Ltd.)
1. Power-On Self-Check Function: The instrument should have an automatic self-check function upon startup, with an additional manual self-check for alarm components.
2. Specify the effective detection distance: The effective detection distance of the non-contact gas alarm instrument shall not be less than 20 m.
3. Alarm Value Setting: For different gases, the standard specifies specific alarm value settings.
For example, the hypoxia alarm setpoint is 19.5% VOL, and the hyperoxia alarm setpoint is 23.5% VOL (refer to GB 8958-2006 "Operation Regulations for Hypoxia Hazardous Work," GB 30871-2022 "Special Operation Regulations for Hazardous Chemical Enterprises").
The first-level flammable gas alarm setpoint is not greater than 25% LEL, and the second-level alarm setpoint is not greater than 50% LEL.
The first and second-level alarm setpoints for toxic and harmful gases are determined based on the OEL (Occupational Exposure Limit) or IDLH (Immediate Danger to Life and Health).
4. Error and Repetition: The standard specifies clear requirements for the instrument's indication error, drift, and repeatability. For instance, the indication error for combustible gases, toxic and harmful gases, and oxygen should not exceed 5%FS, 5%FS, and 2%FS respectively within the normal test range of the instrument's full scale.
5. Calibration and Interface: The instrument should be easy to calibrate, with a set calibration program and corresponding interface to ensure the accuracy of its measurement results.
6. Explosion-proof Performance: Equipment for explosive environments must have explosion-proof performance in accordance with relevant regulations and obtain an explosion-proof certification.
7. Audio-Visual Alarm Devices: The audio-visual alarm device of the alarm should meet specific visibility and sound pressure level requirements to ensure effective alerting of staff during emergencies.
8. Output Control Function: Instruments with output control functions should be able to activate the output control when an alarm signal is emitted, such as cutting off power or starting the exhaust system, etc.
9. Power Requirements: Specific requirements are outlined for power supply voltage, continuous operating time, etc., for battery-powered and non-battery-powered instruments.
10. Other Performance Requirements: Including requirements for azimuth, response time, full-scale indication error, high-speed airflow, long-term stability, insulation withstand voltage performance, temperature, constant humidity and heat, resistance to electromagnetic interference, resistance to steam interference, vibration and drop, and functionality.

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 and interfering gases.
Inspection gauges and instruments
1) Gas Standard Material
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: Resolution 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: Tube for gas pipeline that does not affect the concentration of the measured gas, such as polytetrafluoroethylene or stainless steel pipe.

Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for the Verification of Combustible Gas Detectors" (JJG693-2011) stipulates: The verification cycle for combustible gas detection and alarm instruments: the verification 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 verification promptly.
Section 3.5 of the "Regulations for the Use of Flammable Gas Detection and Alarm Systems" (SY6503-2000) stipulates: The flammable gas detection and alarm systems in use shall be calibrated periodically as per the regulations.
Occupational Health Service (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be carried out regularly according to the manufacturer's specified time and procedures.
Section 3.4 of the "Regulations for the Use of Combustible Gas Detectors" (SY6503-2000) stipulates: Combustible gas detectors for installation and use should have measurement instruments manufactured by an institution recognized for their**explosion-proof performance**.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution that provides regular certification, metrological verification, and calibration services for electrical safety, electrical explosion-proof equipment, gas detectors, and toxic and harmful gas alarm instruments. We are qualified to assist customers in addressing fire and explosion prevention issues.