Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for equipment such as gas alarms, combustible gas detectors, and toxic gas detectors for various locations. We are fully qualified to serve nationwide, addressing all sorts of electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
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 sites.
The standard was published 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 workplace environments.

Standard for verification and calibration of combustible and toxic gas detectors:
Standard GB/T50493-2019 "Design Standard for Detection and Alarm of Combustible and Toxic Gases in Petroleum and Chemical Industry"
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace
JJG693-2011 "Regulation for Calibration of Combustible Gas Detectors"

What does a calibration report for a flammable gas detector include?
The verification results should be reflected in the verification certificate or report. 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 Certificate or report (e.g., numbered), with page numbers indicated on each page
⑤ Shipper'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 or 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 written consent from the laboratory.
Reproofreading interval
The recalibration period for instruments is typically one year, determined by the sending 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.

Verification Method
Appearance and structure
Inspect and feel according to the requirements of Section 4.1
Logos and Branding
Conform to Section 4.2 as observed visually.
Power-on inspection
Inspect visually and by touch, as per requirements 4.3, to check the 5.3.4 alarm function and alarm action values.
Introduce a standard gas substance with a concentration exceeding the alarm set point, causing the instrument to trigger an alarm. Observe whether the instrument's sound and light alarm functions properly and record the instrument's reading when the alarm is triggered. Repeat the measurement three times, and the arithmetic mean of the three readings is the instrument's alarm trigger value.
Shenzhen Zhongnuo Inspection & Testing Technology Co., Ltd. is a third-party service provider specializing in electrical safety, electrical explosion-proofing, gas alarms, and toxic and harmful gas detection instruments, offering regular inspections, metrological measurements, and calibrations. We are licensed to assist clients in addressing fire and explosion prevention issues.