Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, verification, and metrological services for gas alarms, combustible gas detectors, and toxic gas analyzers for various locations. We hold qualifications to serve nationwide, addressing all sorts of electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
Standard for verification and calibration of combustible and toxic gas detectors:
GB/T50493-2019 "Design Standard for Detection and Alarm Systems of Combustible Gases and Toxic Gases in Petroleum and Chemical Industries"
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace
JJG693-2011 "Code of Calibration for Combustible Gas Detectors"

Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for Calibration of Combustible Gas Detectors" (JJG693-2011) stipulates: The calibration cycle for combustible gas detection and alarm instruments: Generally, the calibration cycle of the instrument should not exceed one year. If there is any doubt about the instrument's measurement data, or if the instrument has been replaced with major components or repaired, it should be sent for calibration promptly.
Section 3.5 of the "Regulations for the Use of Flammable Gas Detection and Alarm Systems" (SY6503-2000) stipulates: The flammable gas detection and alarm systems in use shall be calibrated periodically in accordance with the regulations.
Occupational Health Service Unit - Code for the Setting of Toxic Gas Devices (GBZ/T223-2009), Article 7.2.1 stipulates: Calibration of detection and alarm devices should be carried out regularly according to the manufacturer's specified time and procedures.
Regulation 3.4 of the "Code for the Use of Flammable Gas Detectors and Alarms" (SY6503-2000) stipulates: Flammable gas detectors and alarms for installation and use should have measuring instruments manufactured by recognized agencies and **explosion-proof performance**.

Regular Inspection Items for Environmental Gas Detection and Alarm Equipment in Workplaces:
Alarm sound and light (if applicable)
2. Small response value
3. Indication 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)

How often is it necessary to regularly calibrate and verify various gas detectors?
Instrument recalibration is typically every 1 year, determined by the submitting unit based on actual usage. During the secondary calibration process, if there are doubts about the instrument's test data, or if the main components of the instrument are replaced, or if recalibration is needed after repairs.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party service provider specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic and harmful gas alarm instruments for regular inspections, metrological measurements, and calibrations. We hold the necessary qualifications to assist clients in addressing fire and explosion prevention issues.