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 issues, and contributing to safe production.
Which gas detectors require regular calibration and verification?
Fixed-install, handheld, and portable gas detectors, gas alarm instruments, toxic and harmful gas detectors/alarm systems, flammable gas detectors/alarm systems, gas analyzers, etc.

Routine Inspection Items for Environmental Gas Detection and Alarm Instruments in Workplaces:
1. 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 Alarm / Gas Alarm)
6. Pump-Aspirated Instrument Gas Sampling Distance and Flow Rate (for Pump-Aspirated Instruments)
7. Power Supply (for battery-powered instruments)
8. Response Time
9. Status Indicator (with Wireless Communication Function)

Gas Alarm Meters Calibration Conditions and Requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
2. Relative Humidity: ≤85%
3. The working environment should not interfere with the normal operation of the instrument through electromagnetic fields and interfering gases.
Inspection Gauges and Instruments
1) Standard Gas Substance
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: graduation not exceeding 0.1s.
4) Flow Control: Flow rate not less than 500 mL/min, flow grade not less than 4.
5) Zero Point Gas: Purified compressed air.
6) Pressure Relief Valve: A pressure relief 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.

How often should various gas detectors be calibrated and tested?
The recalibration period for instruments is typically one year, subject to the sending unit's determination based on actual usage. During the secondary 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 recalibration is required.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party service provider specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic and harmful gas alarm instruments for regular inspections, metrological measurements, and calibrations. We hold the necessary qualifications to assist customers in addressing fire and explosion prevention issues.