Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and metrological services for equipment such as gas alarms, combustible gas detectors, and toxic gas detection instruments in various locations. We hold qualifications to serve nationwide, addressing customers' electrical safety and explosion-proof fire prevention issues, and contributing to safe production.
Appearance and structure
The instrument should not have any appearance damage that affects its normal operation. The surface of newly manufactured instruments should be smooth and glossy, with even paint and plating coatings, free of peeling and rusting.
The instruments have reliable connections; all dials or buttons should operate and control normally.
Branding and labeling
Instrument name, model, manufacturer's name, date of manufacture, serial number, explosion-proof marking and number, as well as the manufacturing metrological instrument license marking and number for domestic instruments should be clear.

Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for the Verification of Combustible Gas Detectors" (JJG693-2011) stipulates: The verification cycle for combustible gas detection and alarm instruments: Generally, the verification cycle for the instrument should not exceed one year. If there is any suspicion about the instrument's measurement data, or if the instrument has been replaced with major components or repaired, it should be promptly sent for verification.
Section 3.5 of the "Regulations for the Use of Combustible Gas Detection and Alarm Systems" (SY6503-2000) stipulates: The combustible gas detection and alarm systems in use shall be calibrated regularly as required.
Occupational Health and Safety Code for Toxic Gas Equipment Installation (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be carried out regularly according to the manufacturer's specified time and procedures.
Section 3.4 of the "Regulations for the Use of Combustible Gas Detectors" (SY6503-2000) stipulates: Combustible gas detectors for installation and use shall have measurement instruments manufactured by an authorized institution with recognized**measuring**and**explosion-proof**performance.

Routine inspection items for environmental gas detection and alarm equipment in work areas:
Alarm sound and light (if applicable)
2. Low response value
3. Indicated Error (for Gas Detectors/ Gas Detector Alarms)
4. Instrument Drift (in Portable Instruments)
5. Alarm Error (for Gas Detector/ Gas Alarm)
6. Pump Suction Instrument Gas Sampling Distance and Flow Rate (for Pump Suction Instrument)
7. Power Supply (for battery-operated instruments)
8. Response Time
9. Status Indicator (with wireless communication capability)

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 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.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion prevention, gas alarms, and toxic and harmful gas detection instruments for regular verification, measurement, and calibration services. We are qualified to provide solutions for fire and explosion prevention issues for our clients.