Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, certification, and metrological services for gas alarms, combustible gas detectors, and toxic gas detection instruments at various locations. We serve nationwide, addressing all sorts of electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
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 detectors typically does not exceed one year. This means that under normal circumstances, a comprehensive calibration and test of the flammable gas detector is required annually to ensure its performance meets the relevant requirements.

Primary technical requirements for regular calibration of flammable gas detectors (Shenzhen ZhongNuo Testing 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 also be set 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: The standard specifies specific alarm value settings for different gases.
For example, the oxygen deficiency alarm setting is 19.5% VOL, and the oxygen-rich alarm setting is 23.5% VOL (refer to GB 8958-2006 "Operation Procedures for Oxygen Deficiency Hazardous Operations" and GB 30871-2022 "Special Operation Regulations for Hazardous Chemical Enterprises").
The first-level combustible 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 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 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: Instruments used in explosive environments should have explosion-proof performance in compliance with relevant regulations and obtain an explosion-proof certificate.
7. Audio-Visual Alarm Device: The alarm's audio-visual alarm device must meet visibility and sound pressure level requirements under specific conditions to ensure effective alerting of staff during emergencies.
8. Output Control Function: Instruments with output control capabilities should be able to activate the output control function upon emitting an alarm signal, such as cutting off power supply or initiating the exhaust system, etc.
9. Power Requirements: Specific requirements are outlined for the supply voltage, continuous operating time, etc., for battery-powered and non-battery-powered instruments.
10. Additional Performance Requirements: Including specifications for bearing, 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 drop resistance, and functionality.

Standard for inspection and metrological calibration of flammable and toxic gas detectors:
GB/T50493-2019 "Design Standard for Detection and Alarm Systems of Combustible Gases and Toxic Gases in Petroleum and Chemical Industry"
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace
JJG693-2011 "Regulation for Calibration of Combustible Gas Detectors"

GB 12358-2024 "General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace" is an important standard.
Intended to standardize the performance, functions, and testing methods of environmental gas detection and alarm instruments used in workplace operations.
The standard was issued in 1990 and has undergone several revisions.
The new version is GB 12358—2024, to be officially implemented on June 1, 2025.
This standard applies to the production and use of gas detection and alarm instruments for flammable gases, toxic and harmful gases, and oxygen in workplace environments.
Shenzhen ZhongNuo Inspection Technology Co., Ltd. is a third-party institution providing regular calibration, measurement, and calibration services for electrical safety, electrical explosion-proof equipment, gas alarms, and toxic gas detection instruments. We are qualified to assist customers in solving fire and explosion prevention issues.