Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, combustible gas detectors, and toxic gas detection instruments for various locations. We hold the necessary qualifications to serve nationwide, providing solutions to electrical safety and explosion-proof fire prevention issues for clients, facilitating safe production.
The detection principle of the instruments primarily includes catalytic combustion, infrared absorption, and thermal conductivity types. The sampling methods involve diffusion and aspiration. The instruments are mainly composed of detection elements, amplification circuits, alarm systems, and displays, designed for monitoring the concentration of combustible gases in the environment.

Gas Standard Material
The gas standard substances used should be of the same type as the gas being measured by the instrument, such as methane, ethane, or a gas standard like isopropanol. If the instrument does not specify the type of gas being measured, the concentration of the gas (e.g., methane, ethane) set at the alarm points should be approximately 60% of the full scale. The uncertainty of the expanded gas standard substances is not significant (%). The flow value error of the repeatability dilution device should not be higher than 0.1%. The concentration unit of the dilution device for gas standard substances should be converted to match the units of the tested instrument, and should not exceed 0.1%.

What information is 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.
① Title, such as "Calibration Certificate" or "Calibration Report";
② Laboratory Name and Address
③ Calibration Location (if not calibrated in the laboratory)
④ Standby letter of credit or report (e.g., numbered), with page and total number indicated on each page
⑤Shipper's name and address;
⑥ Describe and clearly define the target school;
Calibration date and receipt date;
⑧ Technical specifications for calibration foundation, including names and codes;
Description of traceability and validity 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 certifier 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 written consent from the laboratory.
Two-proofing time interval
Instrument recalibration is typically every 1 year, determined by the sending unit based on actual usage. During the secondary calibration process, if there are any doubts about the instrument's test data, or if the main components of the instrument are replaced, as well as after repairs, a recalibration is required.

GB 12358-2024 "General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplaces" 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 released in 1990 and has undergone multiple 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 work environments.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party service provider specializing in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic/hazardous gas detection instruments. We offer regular inspections, metrological measurements, and calibrations, and are qualified to help clients address fire and explosion prevention issues.