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 in various locations. We hold the necessary qualifications to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention issues, and contributing to safe production.
The calibration cycle for flammable gas detectors is typically once a year.
In accordance with the standard JJG 693-2011 "Flammable Gas Detectors," the calibration period for flammable gas alarms typically does not exceed one year. This means that, under normal circumstances, a comprehensive calibration and test of the flammable gas alarm is required annually to ensure its performance meets relevant requirements.

Method of Verification
Appearance and structure
Inspect visually and by touch according to the requirements of 4.1
Logos and Branding
Conform to 4.2 requirements by visual inspection.
Power-on Inspection
Inspect visually and by touch, in accordance with requirements 4.3, to check the 5.3.4 alarm function and alarm action values.
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 function normally 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.

Regular inspection items for environmental gas detection and alarm instruments in work场所:
Alarm sound and light (if applicable)
2. Low response value
3. Indicating Error (for Gas Detectors/Gas Detector Alarms)
4. Instrument Drift (in Portable Instruments)
5. Alarm Error (for Gas Detection Alarms/Gas Alarm Meters)
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 capability)

GAS ALARM METER CALIBRATION CONDITIONS AND REQUIREMENTS
Environmental Conditions
Ambient Temperature: 0~40℃.
Relative humidity: ≤85%.
3. The working environment should not affect the normal operation of the instrument due to electromagnetic fields and interfering gases.
Calibration Tools and Instruments
1) Standard Gas Materials
The relative expanded uncertainty of the gas standard material does not exceed 2% (k=2).
2) Standard Gas Dilution Unit: Dilution Error of 1%.
3) Stopwatch: Resolution not greater than 0.1s.
4) Flow Control: Flow range not less than 500 mL/min, flow grade not less than level 4.
5) Zero Point Gas: Purified compressed air.
6) Pressure Reducing Valve: A pressure reducing valve that matches with the calibrated cylinder.
7) Gas Pipeline: Tubing made of materials like polytetrafluoroethylene or stainless steel that do not affect the concentration of the measured gas.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic and harmful gas detectors, offering regular inspections, metrological services, and calibration. We are qualified to address fire and explosion prevention issues for our clients.