Zhejiang combustible gas detector calibration cycle

Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, certification, and measurement services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We offer nationwide services to address electrical safety and explosion-proof fire prevention issues for our clients, contributing to safe production.
How often should various gas detectors be periodically calibrated and tested?
Instrument recalibration is typically every 1 year, determined by the submitting unit based on actual usage. During the secondary calibration process, if there are any doubts about the instrument's test data, or if the main components of the instrument are replaced, as well as after repairs, recalibration is required.

Gas Standard Material
We use gas standard substances of the same type as the gas measured by the instrument, such as methane, ethane, or gas standards can also use isopropanol, etc. If the instrument does not specify the type of gas being measured, the concentration of the gas at the set point, such as methane, ethane, or warning, is approximately 60% of the full scale. The uncertainty of the expanded gas standard substance is not more than %(k-1% for body standard substance). The flow indication error of the repetitive dilution device should not be greater than 0.%. The concentration unit of the gas standard substance diluted by the dilution device should be converted to the unit of the instrument being tested when in use, and the unit should not be greater than 0.%.

Primary Technical Requirements for Regular Calibration of Combustible 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. Specify the effective detection distance: The effective detection distance of the non-contact gas alarm instrument shall not be less than 20 meters.
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 high-oxygen alarm setpoint 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 established calibration procedures and corresponding interfaces to ensure the accuracy of its measurement results.
6. Explosion-proof Performance: Equipment used in explosive environments must have explosion-proof performance in compliance with relevant regulations and obtain an explosion-proof certification.
7. Audio-Visual Alarm Device: The audio-visual alarm device of the alarm should meet the visibility and sound pressure level requirements under specific conditions, ensuring effective notification to staff in 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 an exhaust system, etc.
9. Power Requirements: Specific requirements are set for the supply voltage, continuous operating time, etc., for both battery-powered and non-battery-powered instruments.
10. Additional 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 resistance, and functional aspects.

Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for the Verification of Flammable Gas Detectors" (JJG693-2011) stipulates: The verification cycle for flammable gas detection and alarm instruments: the verification cycle of the instrument shall generally not exceed one year. Instruments with suspected measurement data, instruments that have replaced major components, or those repaired should be submitted for verification promptly.
Section 3.5 of the "Regulations for the Use of Combustible Gas Detection and Alarm Systems" (SY6503-2000) stipulates: Combustible gas detection and alarm systems in use shall be calibrated periodically as per 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 the "Regulations for the Use of Combustible Gas Detectors" (SY6503-2000) stipulates: Combustible gas detectors for installation and use shall have measurement instruments manufactured by an institution recognized for their**explosion-proof performance**.
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 alarm instruments for regular calibration, measurement, and certification services, providing qualifications to solve fire and explosion-proofing issues for clients.