Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment in various locations. We hold qualifications to serve nationwide, providing solutions to electrical safety and explosion-proof fire prevention issues for clients, and contributing to safe production.
Gas Detector Alarm Calibration Specification Requirements
Section 5.5 of the "Regulation for Calibration of Combustible Gas Detectors" (JJG693-2011) stipulates: The calibration period for combustible gas detection and alarm instruments: Generally, the calibration period of the instrument should not exceed one year. If there is any doubt about the measurement data of the instrument, or if the instrument has been replaced with major components or repaired, it should be submitted for calibration 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 regularly as required.
Occupational Health Service - Technical Specification for the Installation of Toxic Gas Devices (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be performed regularly according to the manufacturer's specified time and procedures.
Regulation 3.4 of the "Standard for the Use of Combustible Gas Detectors and Alarms" (SY6503-2000) stipulates: Combustible gas detectors and alarms installed and used shall have measurement instruments manufactured by an authorized institution with recognized **measurement accuracy** and **explosion-proof performance**.

The calibration cycle for flammable gas detectors is typically once a year.
According to the standard JJG 693-2011 "Flammable Gas Detectors," the calibration cycle for flammable gas alarms generally does not exceed 1 year. This means that, under normal circumstances, a comprehensive calibration and testing of the flammable gas alarm is required annually to ensure its performance meets the relevant requirements.

Calibration Method
Appearance and structure
Inspect and feel in accordance with requirements of 4.1
Logos and Branding
Inspection to be conducted in accordance with requirement 4.2.
Power-on inspection
Inspect visually and by touch, as per requirements of 4.3, to check the alarm function and alarm action values as specified in 5.3.4.
Introduce a standard gas substance with a concentration exceeding the alarm set point, causing the instrument to trigger an alarm. Observe whether the instrument's sound and light alarm functions normally and record the instrument's reading at the time of the alarm. Repeat the measurement three times, and the arithmetic mean of the three readings is the instrument's alarm trigger value.

Standard for calibration and verification of flammable and toxic gas detectors:
GB/T 50493-2019 "Design Standard for Detection and Alarm of Combustible and Toxic Gases in Petroleum and Chemical Industries"
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace
JJG 693-2011 "Regulation for the Verification of Combustible Gas Detectors"
Shenzhen Zhongnuo Inspection & Technology Co., Ltd. is a third-party institution that specializes in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic and harmful gas detection instruments, providing regular inspections, metrological services, and calibration. We are qualified to address fire and explosion prevention issues for our clients.