Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, certification, and metrological services for gas detectors, flammable gas detectors, and toxic gas detection instruments for various locations. We provide nationwide services to address electrical safety and explosion-proof fire prevention issues for clients, facilitating safe production.
Verification Method
Appearance and structure
Inspect and feel according to the requirements of 4.1
Logos and Branding
Inspection shall be conducted in accordance with requirement 4.2 as per visual observation.
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 substance with a gas concentration exceeding the alarm setpoint, causing the instrument to trigger an alarm. Observe if the instrument's audible and visual alarms are functioning properly and record the instrument's reading when the alarm is triggered. Repeat the measurement three times; 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 plating layer, free of peeling and rusting.
The instrument's connections are reliable, and all dials or buttons should operate and control normally.
Logos and Branding
Instrument name, model, manufacturer's name, date of manufacture, serial number, explosion-proof marking and number, as well as the manufacturing metrological instrument license marking and number for domestic instruments, should be clear.

Regular Inspection Items for Environmental Gas Detection and Alarm Equipment in Workplace Operations:
Alarm sound and light (if applicable)
2. Low response value
3. Indicating Error (for Gas Detectors/Gas Detection Alarms)
4. Instrument Drift (in Portable Instruments)
5. Alarm Error (for Gas Detection Alarm/ Gas Alarm)
6. Pump-actuated instrument gas collection distance and flow rate (for pump-actuated instruments)
7. Power Supply (for battery-powered instruments)
8. Response Time
9. Status Indicator (with Wireless Communication Function)

Regulatory Contents and Methods for Routine Detection of Flammable Gas Detectors
Annually, we conduct annual inspections on the sensors of commercial and industrial alarm systems, primarily checking for the accuracy, repeatability, drift, and response time of the alarms to ensure they meet standards. Additionally, we verify the suitability of the alarm installation location and check for any interference from other equipment.
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 inspections, metrological measurements, and calibrations. We hold the necessary qualifications to assist clients in addressing fire and explosion prevention issues.