Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We hold the necessary qualifications to serve nationwide, addressing all sorts of electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
Which gas detectors require regular calibration and verification?
Fixed-install, handheld, and portable gas detectors, gas alarm instruments, toxic and harmful gas detectors/alarm systems, flammable gas detectors/alarm systems, gas analyzers, etc.

Regular Inspection Content for Gas Detectors
Installation spacing of inspection (probe) points
2. Installation Height of the Detector
3. Indication Error (Concentration)
4. Repeatability (Concentration)
5. Alarm Error (Concentration)
6. Response Time (Seconds)

GB 12358-2024 "General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplaces" is an important standard.
Intended to standardize the performance, functions, and testing methods of environmental gas detection alarm instruments used in work places.
The standard was published in 1990 and has undergone multiple revisions.
The new version is GB 12358-2024, which will 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.

Key Technical Requirements for Regular Calibration of Combustible 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, with an additional manual self-check function for alarm components.
2. Specify Effective Detection Distance: The effective detection distance of non-contact gas alarms shall not be less than 20 meters.
3. Alarm Value Setting: Specific alarm value settings are standardized for different gases.
For example, the hypoxia alarm set value is 19.5%VOL, and the oxygen-rich alarm set value is 23.5%VOL (refer to GB 8958-2006 "Operation Code for Hazardous Work of Hypoxia" and GB 30871-2022 "Special Operation Code for Chemical Hazardous Substance Enterprises").
The first-level alarm setting for flammable gases does not exceed 25% LEL, and the second-level alarm setting does not exceed 50% LEL.
The first and second-level alarm settings for toxic and harmful gases are determined based on OEL (Occupational Exposure Limit) or IDLH (Immediately Dangerous 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, and calibration programs and corresponding interfaces should be set up to ensure the accuracy of its measurement results.
6. Explosion-proof Performance: Instruments used in explosive environments should possess explosion-proof properties in compliance with relevant regulations and obtain an explosion-proof certification.
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 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. Other Performance Requirements: Including requirements for bearing, response time, full-scale indication error, high-speed airflow, long-term stability, insulation withstand voltage performance, temperature, constant humidity and heat, electromagnetic interference resistance, steam interference resistance, vibration and drop, and functionality.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic gas detection equipment for regular inspections, metrological measurements, and calibration services. We are qualified to provide solutions for fire and explosion prevention issues for our clients.