Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, verification, and metrological services for gas alarms, combustible gas detectors, and toxic gas detection instruments in various locations. We hold qualifications to serve nationwide, addressing customers' electrical safety and explosion-proof fire prevention needs, and contributing to safe production.
Power-on inspection
After power is applied to the instrument, it should operate normally with clear and complete display. Check the alarm function and alarm trigger values.
Alarm function and alarm action value verification
The instrument's sound and light alarm should function normally. Insulation resistance.
Insulation resistance for instruments using AC power should not be less than 20MΩ.

Gas Detector Alarm Calibration Specification Requirements
Section 5.5 of the "Regulation for Verification of Combustible Gas Detectors" (JJG693-2011) stipulates: The verification cycle for combustible gas detection and alarm instruments: Generally, the verification cycle of the instrument should not exceed one year. Instruments with suspected measurement data, replaced major components, or repaired should be promptly submitted for verification.
Section 3.5 of the "Regulations for the Use of Combustible Gas Detection and Alarm Systems" (SY6503-2000) stipulates: In-use combustible gas detection and alarm devices shall be calibrated periodically as per regulations.
Occupational Health Service (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices should be carried out regularly according to the manufacturer's specified time and procedures.
Section 3.4 of the "Regulations for the Use of Combustible Gas Detectors" (SY6503-2000) stipulates that the installation and use of combustible gas detectors should have measurement instruments manufactured by an institution recognized for their**measurement accuracy** and**explosion-proof performance**.

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 other gases 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 is approximately 60% of the full scale, using a standard substance. The expanded uncertainty of the standard gas generation is not significant (%), and the standard gas standard substance should have a repeatability of more than 1%. The flow rate indication error of the dilution device should not be greater than 0.%. The concentration unit of the gas standard substance should be converted to match the unit of the tested instrument when in use, and the value should not exceed 0.%.

Gas Detector Regular Inspection Content
Installation spacing of inspection (probe) points
2. Installation Height of the Detector
3. Indicated Error (Concentration)
4. Repeatability (Concentration)
5. Alarm Error (Concentration)
6. Response Time (seconds)
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic gas detection equipment, offering regular inspections, metrological services, and calibration. We are licensed to address fire and explosion prevention issues for our clients.