Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, certification, and metrological services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We offer services nationwide, addressing various electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
Regular Inspection Items for Environmental Gas Detection and Alarm Equipment in Workplace Operations:
1. Alarm sound and light (if applicable)
2. Small response value
3. Indicated Error (for Gas Detectors/ Gas Detector Alarms)
4. Instrument Drift (in portable instruments)
5. Alarm Error (for Gas Detection Alarm / Gas Alarm)
6. Pump-suction Instrument Gas Sampling Distance and Flow Rate (for pump-suction instruments)
7. Power Supply (for battery-powered instruments)
8. Response Time
9. Status Indicator (with Wireless Communication Function)

Primary 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, and a manual self-check function should be set for alarm components.
2. Specify the effective detection distance: The effective detection distance of non-contact gas detectors shall not be less than 20 m.
3. Alarm Value Settings: Specific alarm value settings are stipulated by the standard for different gases.
For example, the oxygen deficiency alarm setpoint is 19.5% VOL, and the enriched oxygen alarm setpoint is 23.5% VOL (refer to GB 8958-2006 "Operation Code for Oxygen Deficiency Hazardous Work" and GB 30871-2022 "Special Operation Code 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 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 flammable 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 must have explosion-proof properties in compliance with relevant regulations and obtain an explosion-proof certification.
7. Sound and Light Alarm Devices: The sound and light alarm devices 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 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: Includes specifications for bearing, response time, full-scale indication error, high-speed airflow, long-term stability, insulation withstand voltage, temperature, constant humidity and heat, resistance to electromagnetic interference, resistance to steam interference, vibration and shock, and functionality.

What factors can affect the calibration cycle of a flammable gas detector alarm?
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 Usage Environment: The operating environment of the alarm can directly affect 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 is frequently experiencing issues like battery depletion or sensor aging, the inspection cycle will accordingly be shortened.

The calibration cycle for flammable gas detectors is typically once a year.
According to the regulations of standard JJG 693-2011 "Flammable Gas Detectors," the calibration cycle for flammable gas alarms typically does not exceed one year. This means that, under normal circumstances, a comprehensive calibration and testing of flammable gas alarms is required annually to ensure that their performance indicators meet the relevant requirements.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic and harmful gas alarm instruments for regular inspections, metrological measurements, and calibration services. We are qualified to solve fire and explosion prevention issues for our clients.