Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, flammable gas detectors, and toxic gas detection instruments for various locations. We hold the necessary qualifications to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention concerns, and contributing to safe production.
Gas Alarm Meters Calibration Conditions and Requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
2. Relative Humidity: ≤85%
3. The working environment should not affect the normal operation of the instrument with electromagnetic fields and interfering gases.
Calibration Tools and Instruments
1) Certified Gas Standard Material
The relative expanded uncertainty of the gas standard substance 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: Use gas pipes made of materials like polytetrafluoroethylene or stainless steel that do not affect the concentration of the measured gas.

What does a calibration report for a combustible gas detector typically include?
The verification results should be reflected in the verification certificate or report, and the verification proof or report must include the following information.
① Calibration Certificate or Calibration Report
② Laboratory Name and Address
③ Calibration Location (if not calibrated in the laboratory)
④ Standing proof or report (e.g., with serial number), and indicate the page number on each page.
⑤ Shipper's name and address
⑥ Clearly describe and specify the target school.
Calibration date and receipt date;
⑧ Technical specifications for calibration base, including names and codes;
Description of 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 calibration 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 written consent from 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, as well as after repairs, recalibration is required.

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 as standards. 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. The uncertainty of the expanded gas standard substance is not more than % (k-body standard substance greater than ±1%). The flow rate indication error of the repetitive dilution device should not be higher than the concentration of the gas standard substance. The concentration unit of the dilution device for gas standard substances should be converted to match the units of the inspected instrument, and the deviation should not exceed 0.%.

Flammable and toxic gas detectors calibration and measurement standard:
GB/T50493-2019 "Design Standard for Detection and Alarm of Combustible Gases and Toxic Gases in Petroleum and Chemical Industry"
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarming Instruments in Workplace
JJG693-2011 "Regulation for Calibration of Combustible Gas Detectors"
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas detectors, and toxic gas alarm instruments for regular inspections, metrological measurements, and calibration services. We hold the necessary qualifications to assist clients in addressing fire and explosion prevention issues.