Shenzhen ZhongNuo Inspection & Technology Co., Ltd. specializes in the certification, calibration, and metrological services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment at various locations. We hold qualifications to serve nationwide, addressing electrical safety and explosion-proof fire prevention issues for clients, and contributing to safe production.
Calibration Method
Appearance and structure
Inspect visually and by touch according to the requirements of Section 4.1.
Logos and Brand Identifiers
Proceed according to the requirements of Section 4.2 as observed visually.
Power-on Inspection
Inspect visually and by touch, as per requirements 4.3, to check the 5.3.4 alarm function and alarm action values.
Introduce a standard gas substance with a concentration greater than the alarm set point, causing the instrument to trigger an alarm. Observe whether the instrument's sound and light alarms are functioning properly and record the instrument's reading when the alarm is triggered. Repeat the measurement three times, and the arithmetic mean of the three readings is the instrument's alarm trigger value.

Appearance and structure
The instrument should not have any appearance damage that affects its normal operation. The surface of newly manufactured instruments should be smooth and even, with a uniform paint and coating, free of peeling or rusting.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Branding and labeling
Instrument name, model, manufacturer's name, date of manufacture, serial number, explosion-proof marking and number, as well as the domestic instrument's manufacturing metrological instrument license marking and number should be clear.

The principle of instrument detection mainly includes catalytic combustion, infrared absorption, and thermal conductivity types. Sampling methods include diffusion and aspiration. The instrument is mainly composed of detection elements, amplification circuits, alarm systems, and displays, used for monitoring the concentration of combustible gases in the environment.

Gas Detector Alarms Calibration Specification Requirements
Regulation 5.5 of "Code for Verification of Combustible Gas Detectors" (JJG693-2011) stipulates: The verification cycle for combustible gas detection and alarm instruments: Generally, the verification 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 replaced major components or been repaired, it should be sent for verification promptly.
Section 3.5 of the "Regulations for the Use of Flammable Gas Detection and Alarm Systems" (SY6503-2000) stipulates: Flammable gas detection and alarm systems in use shall be calibrated regularly as required.
Occupational Health Service Facilities Toxic Gas Equipment Installation Code (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) stipulates: Combustible gas detectors for installation and use should have measurement instruments manufactured by an authorized body and 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 gas detection instrument calibration, metrology, and regular inspections. We provide qualification services to solve fire and explosion prevention issues for clients.