Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services of gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment for various venues. We hold the necessary qualifications to serve nationwide, providing solutions to electrical safety and explosion-proof fire prevention issues for clients, facilitating safe production.
Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for Inspection and Verification of Combustible Gas Detectors" (JJG693-2011) stipulates: The inspection period for combustible gas detection and alarm instruments: The general inspection period for the instrument should not exceed one year. If there is any doubt about the instrument's measurement data, or if the instrument has been replaced with major components or repaired, it should be sent for inspection 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 Service Establishment Code for Toxic Gas Facilities (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 "Code for the Use of Combustible Gas Detectors and Alarms" (SY6503-2000) stipulates: Combustible gas detectors and alarms for installation and use shall have measuring instruments manufactured by an institution recognized for their explosion-proof performance.

Key Technical Requirements for Regular Calibration 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, and a manual self-check function should be set for alarm components.
2. Specified Effective Detection Distance: The effective detection distance of non-contact gas detectors shall not be less than 20 m.
3. Alarm Value Setting: The standard specifies specific alarm value settings for different gases.
For example, the oxygen deficiency alarm setting is 19.5% VOL, and the enriched oxygen alarm setting is 23.5% VOL (refer to GB 8958—2006 "Operation Regulations for Oxygen Deficiency Hazardous Operations" and GB 30871—2022 "Special Operation Regulations for Hazardous Chemical Enterprises").
The first-level combustible gas alarm setting is not greater than 25% LEL, and the second-level alarm setting is not greater than 50% LEL.
The first and second-level alarm settings 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 Repeatability: The standard sets 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 established calibration procedures and corresponding interfaces to ensure the accuracy of its measurement results.
6. Explosion-proof Performance: Equipment intended for explosive environments must have explosion-proof performance in accordance with relevant regulations and obtain an explosion-proof certificate.
7. Audio-Visual Alarm Device: The audio-visual alarm device of the alarm should meet visibility and sound pressure level requirements under specific conditions, ensuring effective alerting of staff during emergencies.
8. Output Control Function: Instruments with output control capabilities should activate such functions upon issuing an alarm signal, including but not limited to shutting off power supply or initiating exhaust systems.
9. Power Supply Requirements: Specific requirements are set for the supply voltage, continuous operating time, etc., of battery-powered and non-battery-powered instruments.
10. Additional Performance Requirements: Includes specifications for direction, response time, full-scale indication error, high-speed airflow, long-term stability, insulation withstand voltage, temperature, constant humidity and heat, electromagnetic interference resistance, steam interference resistance, vibration and shock resistance, and functional aspects.

The calibration cycle for flammable gas detectors is typically once a year.
In accordance with the standard JJG 693-2011 "Flammable Gas Detectors," the calibration cycle for flammable gas alarms generally does not exceed one year. This means that under normal circumstances, a comprehensive calibration and testing of the flammable gas alarm should be conducted annually to ensure its performance meets the relevant requirements.

Gas Standard Material
The gas standard substance used should be of the same type as the gas measured by the instrument, such as methane, ethane, or other gases; standard gases can also be isopropanol, etc. If the instrument does not specify the type of gas being measured, the concentration of the gas at the set point of the alarm should be about 60% of the full scale. The uncertainty of the standard gas generating gas should not be more than % (k-gas standard substance greater than ±1%); the flow value error of the repetitive dilution device should not be higher than the concentration of the gas standard substance. The concentration unit of the dilution device for the gas standard substance should be converted to the unit of the measuring instrument being tested. The value should not be greater than 0.%.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proof, gas alarm, and toxic gas detection equipment for regular verification, calibration, and measurement services. We hold the necessary qualifications to address fire and explosion prevention issues for our clients.