Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the certification, calibration, and metrological services for equipment such as gas alarms, flammable gas detectors, and toxic and harmful gas detectors for various locations. We hold qualifications to serve nationwide, addressing customers' electrical safety and explosion-proof fire prevention concerns, and contributing to safe production.
Regular Inspection Items for Environmental Gas Detection and Alarm Equipment in Workplaces:
Alarm sound and light (if applicable)
2. Low response value
3. Indication Error (for Gas Detectors/ Gas Detector Alarms)
4. Instrument Drift (in Portable Instruments)
5. Alarm Error (for Gas Detector/ 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 capability)

Which gas detectors require regular calibration and verification?
Fixed-installed, handheld, and portable gas detectors, gas alarm instruments, toxic and harmful gas detectors/alarm, flammable gas detectors/alarm, gas analyzers, etc.

Gas Standard Material
We use gas standard substances of the same type as the gas measured by the instrument, such as methane or ethane, or alternative substances like isopropanol can be used. If the instrument does not specify the type of gas being measured, the concentration of the gas at the set point should be approximately 60% of the full scale, using a standard substance. The uncertainty of the expanded gas standard substance is not significant (%), and the standard gas should be diluted using a dilution device. The flow value error of the dilution device should not exceed a concentration of the gas standard substance. The concentration unit of the dilution gas standard substance should be converted to match the unit of the inspected instrument, and the discrepancy should not be greater than 0.%.

Method of Verification
Appearance and structure
Inspect visually and by touch according to the requirements of 4.1
Logos and Branding
Conform to Section 4.2 as observed visually.
Power-on inspection
Inspect visually and by touch according to the requirements of 4.3 to check the 5.3.4 alarm function and alarm action values.
Introduce a standard substance of gas at a concentration greater than the alarm set point, causing the instrument to trigger an alarm action. Observe if the instrument's audio-visual alarm is functioning properly and record the instrument's reading at the time of alarm. Repeat the measurement three times, with the arithmetic mean of the three readings being the instrument's alarm action value.
Shenzhen Zhongnuo Inspection Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proof, gas alarm, and toxic gas detection equipment, providing regular verification, measurement, and calibration services. We are licensed to help customers address fire and explosion prevention issues.