Shenzhen ZhongNuo Inspection Technology Co., Ltd. specializes in the calibration, certification, and metrological services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment in various locations. We offer nationwide services to address electrical safety and explosion-proof fire prevention issues for clients, promoting safe production.
Gas Standard Material
The gas standard substances used are the same as the types of gases measured by the instrument, such as methane, ethane, or gases with standards like isopropanol. If the instrument does not specify the type of gas being measured, the concentration of the gas with a 60% margin set for the gas types methane, ethane, or others is approximately the full-scale value of the standard substance. The expanded uncertainty of the standard gas generating gas should not be more than %(k-1)%. The flow indication error of the repeatability dilution device for standard gas standard substances should not be higher than 0.%. 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.%.

What does a calibration report for a combustible gas detector typically include?
The verification results should be reflected in the verification certificate or report. 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)
④Standing proof or report (e.g., numbered), with each page and page number indicated;
5. Shipper's name and address
⑥ Describe and clearly identify the target school.
Calibration Date and Receipt Date
⑧ Technical specifications for calibration base, including name and code;
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 report; and 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-proofreading 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.

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 electromagnetic fields and interfering gases that affect the normal operation of the instrument.
Calibration Tools and Instruments
1) Certified Reference Materials for Gases
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 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: Tubing made of materials like polytetrafluoroethylene or stainless steel that do not affect the concentration of the measured gas.

GB 12358-2024 "General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace" is an important standard.
Intended to standardize the performance, functions, and testing methods of environmental gas detection alarm instruments used in work场所.
The standard was issued in 1990 and has undergone several revisions.
The new version is GB 12358-2024, which will be officially implemented on June 1, 2025.
This standard applies to the production and use of gas detection and alarm instruments for flammable gases, toxic and harmful gases, and oxygen in workplaces.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution that specializes in electrical safety, electrical explosion-proofing, gas alarms, and toxic gas detection instruments, providing regular inspections, metrological measurements, and calibration services. We are qualified to address fire and explosion prevention issues for our clients.