Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, certification, and measurement services for gas alarms, flammable gas detectors, toxic gas analyzers, and other equipment used in various locations. We offer services nationwide to address clients' electrical safety and explosion-proof fire prevention issues, contributing to safe production.
What factors can affect the calibration cycle of a combustible gas detector alarm?
Manufacturer Requirements: Different manufacturers may have varying inspection cycle requirements for flammable gas detectors. Therefore, when purchasing equipment, carefully review the product manual to understand the specific requirements of the manufacturer.
Equipment Usage Environment: The operating environment of the alarm directly affects its inspection cycle. If the equipment is exposed to a high concentration of harmful gases, high humidity, or extreme temperatures (either high or low) for extended periods, the inspection cycle may be accordingly shortened.
‌Equipment Maintenance Status: The condition of equipment maintenance is also a significant factor affecting the inspection cycle. If the equipment is long-term exposed to issues like battery depletion, sensor aging, etc., the inspection cycle will accordingly be shortened.

Regular inspection contents for gas alarms
Installation spacing of inspection (probe) points
2. Installation Height of the Detector
3. Indicated Error (Concentration)
4. Repetition (Concentration)
5. Alarm Error (Concentration)
6. Response Time (seconds)

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 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 oxygen deficiency alarm setpoint is 19.5% VOL, and the oxygen enrichment alarm setpoint is 23.5% VOL (refer to GB 8958—2006 "Operation Procedures for Oxygen Deficiency Hazardous Work" and GB 30871—2022 "Special Operation Regulations for Hazardous Chemical Enterprises").
The first-level alarm setting for flammable gas 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 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: Equipment intended for explosive environments should possess explosion-proof properties in accordance with relevant regulations and obtain an explosion-proof certification.
7. Audio-Visual Alarm Devices: The audio-visual alarm devices 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 functionality should be capable of activating the output control feature upon emitting an alarm signal, such as cutting off power supply or initiating an exhaust system, etc.
9. Power Supply Requirements: Specific requirements are outlined for the voltage and continuous operating time of instruments powered by batteries and those powered by non-battery sources.
10. Other Performance Requirements: Includes specifications for azimuth, 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, and functionality.

Regulatory and Methodical Routine Inspection of Flammable Gas Detectors
Annual inspections of industrial and commercial alarm sensors are conducted regularly, primarily checking for the accuracy, 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 verified.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic and harmful gas detection instruments, providing regular calibration, measurement, and certification services. We are qualified to address fire and explosion prevention issues for our clients.