Shenzhen ZhongNuo Testing 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 the necessary qualifications to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention concerns, and contributing to safe production.
The calibration cycle for flammable gas detectors is typically once a year.
In accordance with the standard JJG 693-2011 "Flammable Gas Detectors," the calibration interval for flammable gas detectors typically does not exceed one year. This means that, under normal circumstances, a comprehensive calibration and testing of the flammable gas detector should be conducted annually to ensure its performance meets the relevant requirements.

What are the contents included in the calibration report for combustible 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 Calibration Certificate or Calibration Report
② Laboratory Name and Address
③ Calibration Location (if not calibrated in the laboratory)
④ Standing certificate or report (e.g., with serial number), indicating each page and page number;
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 the traceability and effectiveness of the measurement standards used in our 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 calibration 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.
Re-check interval
Instrument recalibration is typically every 1 year, determined by the sending unit based on actual usage. During the re-calibration process, if there are doubts about the instrument's test data, or if the main components of the instrument are replaced, as well as after repairs, a re-calibration is required.

Technical Requirements for Regular Calibration of Flammable Gas Detectors (Shenzhen Zhongnuo Inspection Technology Co., Ltd.)
1. Power-on Self-Check Function: The instrument should have an automatic self-check function upon power-on, and the alarm components should also be equipped with a manual self-check function.
2. Specified Effective Detection Range: The effective detection range of the non-contact gas alarm instrument shall not be less than 20 meters.
3. Alarm Value Setting: Specific alarm value settings are stipulated for different gases according to the standard.
For example, the hypoxia alarm setting is 19.5% VOL, and the hyperoxia alarm setting is 23.5% VOL (refer to GB 8958-2006 "Operation Procedures for Hypoxia Hazardous Work" and GB 30871-2022 "Special Operation Regulations for Hazardous Chemical Enterprises").
The first-level combustible gas alarm setpoint is not greater than 25% LEL, and the second-level alarm setpoint is not greater than 50% LEL.
The first and second alarm setpoints for toxic and harmful gases are determined based on the OEL (Occupational Exposure Limit) or IDLH (Immediate Danger to Life and Health).
4. Error and Repetition: The standard specifies clear requirements for the instrument's indication error, drift, and repeatability. For instance, the indication error for combustible gases, toxic and harmful gases, and oxygen should not exceed 5% FS, 5% FS, and 2% FS respectively within the normal test range of the instrument's full scale.
5. Calibration and Interface: The instrument should be easy to calibrate, with established calibration procedures and corresponding interfaces to ensure the accuracy of its measurement results.
6. Explosion-proof Performance: Equipment for explosive environments should possess explosion-proof performance in compliance with relevant regulations and obtain an explosion-proof certification.
7. Audio-Visual Alarm System: The audio-visual alarm of the alarm device must meet visibility and sound pressure level requirements under specific conditions to effectively alert staff during emergencies.
8. Output Control Function: Instruments with output control capabilities should be able to activate the output control function upon emitting an alarm signal, such as shutting off power or initiating an exhaust system, etc.
9. Power Supply Requirements: Specific requirements are outlined for the voltage and continuous operating time of both battery-powered and non-battery-powered instruments.
10. Other Performance Requirements: Including requirements for azimuth, response time, full-scale indication error, high-speed airflow, long-term stability, insulation withstand voltage performance, temperature, constant humidity and heat, electromagnetic interference resistance, steam interference resistance, vibration and drop, and functionality.

What factors can affect the calibration cycle of a combustible gas detector alarm?
Manufacturer Requirements: Flammable gas detectors from different manufacturers may have varying inspection cycle requirements. Therefore, when purchasing equipment, carefully review the product manual to understand the specific requirements of the manufacturer.
Equipment Operating Environment: The operating environment of the alarm directly affects its inspection cycle. If the equipment is frequently exposed to high concentrations of harmful gases, high or low humidity, or high or low temperatures for extended periods, its inspection cycle may be shortened accordingly.
‌Equipment Maintenance Status: The condition of equipment maintenance is also a significant factor affecting the inspection cycle. If the equipment is long-term faced with issues like battery depletion, sensor aging, etc., the inspection cycle will accordingly be shortened.
Shenzhen Zhongnuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas detectors, and toxic gas alarm instruments for regular inspections, metrological measurements, and calibration services. We hold the necessary qualifications to assist clients in solving fire and explosion prevention issues.