Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, certification, and metrological services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment in various locations. We provide nationwide services to address electrical safety and explosion-proof fire prevention issues for clients, contributing to safe production.
Verification Method
Appearance and structure
Inspect visually and by touch according to the requirements of Section 4.1.
Logos and Branding Marks
Observe as per requirements of Section 4.2.
Power-on inspection
Inspect visually and by touch in accordance with 4.3 requirements to check the 5.3.4 alarm function and alarm action values.
Introduce a standard gas substance with a concentration greater than the alarm setting point, causing the instrument to trigger an alarm. Observe if the instrument's audio-visual alarm is functioning properly and record the instrument's reading when the alarm is triggered. Repeat the measurement three times; the arithmetic average of the three readings is the instrument's alarm trigger value.

Instrument Calibration Control
Instrument control includes calibration, follow-up calibration, and in-use inspection.

Flammable and toxic gas detectors calibration and measurement standard:
GB/T 50493-2019 "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 "Regulation for Calibration of Combustible Gas Detectors"

Which gas detectors require regular calibration and verification?
Fixed installations, handheld, portable gas detectors, gas alarm instruments, toxic and harmful gas detectors/alarm systems, flammable gas detectors/alarm systems, gas analyzers, etc.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas detectors, and toxic gas alarm instruments, offering regular inspections, metrological measurements, and calibrations. We are qualified to help customers address fire and explosion prevention issues.