Shenzhen ZhongNuo Inspection Technology Co., Ltd. specializes in the certification, calibration, and metrological services for gas alarms, flammable gas detectors, toxic and harmful gas detectors, and other equipment in various locations. We hold qualifications to serve nationwide, addressing all sorts of electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
Gas Detector Alarms Calibration Standard Requirements
Regulation 5.5 of the "Regulation for Verification of Combustible Gas Detectors" (JJG693-2011) stipulates: The verification cycle for combustible gas detection and alarm instruments: Generally, the verification cycle of the instrument should not exceed one year. If there is any doubt about the instrument's measurement data, or if the instrument has been replaced with major components or repaired, it should be sent for verification promptly.
Section 3.5 of the "Regulations for the Use of Flammable Gas Detection and Alarm Systems" (SY6503-2000) stipulates: The flammable gas detection and alarm systems in use shall be calibrated regularly as per the regulations.
Occupational Health Service Establishment Standard for Toxic Gas Facilities (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 "Code for the Use of Combustible Gas Detectors and Alarms" (SY6503-2000) stipulates: The installation and use of combustible gas detectors and alarms shall have measuring instruments manufactured by recognized agencies with **protection against explosion** properties.

What are the contents included in the calibration report for flammable gas detectors?
The verification results should be reflected on the verification certificate or report, and the verification proof or report must include the following information.
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), indicating page number and total number of pages for each page
Please provide the name and address of the shipping entity.
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 Statements
12. Signature, title, or equivalent mark 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 required after repairs.

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 gas standards can also use isopropanol, etc. If the instrument does not specify the type of gas being measured, the concentration of the gas at the set point for methane, ethane, or other gases is 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 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 the gas standard substance should be converted to match the unit of the inspected instrument, and the value should not exceed 0.%.

Standard for calibration and verification of flammable and toxic gas detectors:
GB/T50493-2019 Standard for Design of Detection and Alarm Systems for Combustible Gases and Toxic Gases in Petroleum and Chemical Industries
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplaces
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 alarms, and toxic and harmful gas alarm instruments for regular inspections, metrological measurements, and calibrations. We are licensed to provide solutions for fire and explosion prevention issues for our clients.