Shenzhen Zhongnuo Inspection & Testing Technology Co., Ltd. specializes in the calibration, verification, and metrological services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment. With qualifications to serve nationwide, we provide solutions for various electrical safety and explosion-proof fire prevention issues, supporting safe production.
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 gas standards can also use isopropanol, etc. If the instrument does not specify the type of gas being measured, the concentration of the gas at the set point (60% of the full scale) is approximately the concentration of the standard substance. The uncertainty of the expanded gas standard substance is not significant (%). The repeatability of the dilution device should not exceed ±1%. The flow indication error of the dilution device should be low for gases with high concentrations. The concentration unit of the gas standard substance should be converted to match the unit of the inspected instrument, and the deviation should not exceed 0.%.

What are the contents included in the calibration report for flammable gas detectors?
The verification results should be reflected in the verification certificate or report, and the verification proof or report must include the following information.
Calibration Certificate or Calibration Report
② Laboratory Name and Address
③ Calibration Location (if not calibrated in the laboratory)
④ Certificate or report (e.g., numbered), with page numbers indicated on each page
⑤Shipper's name and address
⑥ Describe the target school clearly and specifically.
Calibration date and receipt date;
⑧ Technical specifications for calibration foundation, including names and codes.
Description of the traceability and effectiveness of the measurement standards used for calibration.
⑩ Description of calibration environment
11. Calibration Results and Measurement Uncertainty Statement
12. Signature, title, or equivalent symbol of the issuer of the calibration certificate or report, and the issuance date;
13. Calibration results are only applicable to the calibration object.
14. No part of the certificate or report may be copied without the written consent of the laboratory.
Re-review interval
Instrument recalibration is typically every 1 year, determined by the submitting unit based on actual usage. During the secondary calibration process, if there are doubts about the instrument's test data, or if the main components of the instrument are replaced, or if recalibration is needed after repairs.

Measurement Instrument Control
Instrument control includes calibration, subsequent calibration, and in-service inspection.

Power-on inspection
Upon power-on, the instrument should operate normally and display sections should be clear and complete. Check the alarm function and alarm trigger values.
Alarm function and alarm action value verification
The instrument's audio-visual alarm should be functioning normally. Insulation resistance
Insulation resistance for instruments using AC power should not be less than 20MΩ.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution providing regular calibration, measurement, and certification services for electrical safety, electrical explosion-proofing, gas detectors, and toxic and harmful gas alarm instruments. We are qualified to address fire and explosion prevention issues for our clients.