Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We hold the necessary qualifications to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention concerns, and contributing to safe production.
The detection principle of the instruments mainly includes catalytic combustion, infrared absorption, and thermal conductivity types. The sampling methods are diffusion and aspiration. The instruments are primarily composed of detection elements, amplification circuits, alarm systems, and displays, used for monitoring the concentration of combustible gases in the environment.

Standard for inspection and metrological calibration of flammable and toxic gas detectors:
Standard GB/T50493-2019 for Design of Detection and Alarm Systems for Combustible Gases and Toxic Gases in Petroleum and Chemical Industry
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace
JJG 693-2011 "Regulation for Calibration of Combustible Gas Detectors"

How often should various gas detectors be calibrated and inspected?
The recalibration period for instruments is typically one year, determined by the submitting unit based on actual usage. During the re-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, a re-calibration is required.

Gas Detector Alarm Calibration Standard Requirements
Regulation 5.5 of the "Regulation for Inspection and Verification of Combustible Gas Detectors" (JJG693-2011) states: The inspection cycle for combustible gas detection and alarm instruments: The general inspection cycle for 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 sent for inspection promptly.
Section 3.5 of the "Regulations for the Use of Combustible Gas Detection and Alarm Systems" (SY6503-2000) stipulates: The combustible gas detection and alarm systems in use shall be calibrated regularly as per the regulations.
Occupational Health Service Station Standard for 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.
Section 3.4 of the "Regulations for the Use of Combustible Gas Detectors" (SY6503-2000) states: Combustible gas detectors for installation and use shall have measuring 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 detection instruments for regular verification, measurement, and calibration services. We are qualified to solve fire and explosion prevention issues for our clients.