Shenzhen ZhongNuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, flammable gas detectors, and toxic gas analyzers for various locations. We hold qualifications to serve nationwide, addressing clients' electrical safety and explosion-proof fire prevention needs, and contributing to safe production.
Gas Alarm Meters Calibration Conditions and Requirements
Environmental Conditions
Ambient Temperature: 0~40℃.
2. Relative Humidity: ≤85%
3. The working environment should not affect the normal operation of the instrument with electromagnetic fields and interfering gases.
Calibration Tools and Instruments
1) Standard Gas Substance
The relative expanded uncertainty of the gas standard material does not exceed 2% (k=2).
2) Standard Gas Dilution Unit: Dilution error of 1%.
3) Stopwatch: Graduation not greater than 0.1s.
4) Flow Control: Flow range not less than 500 mL/min, flow grade not less than level 4.
5) Zero Point Gas: Purified compressed air.
6) Pressure Relief Valve: A pressure relief valve that is compatible with the calibration cylinder.
7) Gas Pipeline: Use gas lines made of materials like polyethylene or stainless steel that do not affect the concentration of the measured gas.

What does a calibration report for a flammable gas detector include?
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 Standing proof or report (e.g., numbered), with page number and total number of pages indicated on each page
Please provide the company name and address for shipping.
⑥ Describe and clearly identify the target school;
Calibration Date and Receipt Date
⑧ Technical specifications for calibration foundation, including names and codes;
Description of the 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 issuer of the calibration certificate or calibration report, and the issuance date;
13. Calibration results are only applicable to the verification object.
14. No part of the certificate or report may be copied without written consent from the laboratory.
Two reproofing time intervals
Instrument recalibration is typically every 1 year, determined by the submitting unit based on actual usage. During the secondary calibration process, recalibrate the instrument if there are questions about the test data, if the main components of the instrument are replaced, or if it needs to be recalibrated after repairs.

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 generally does not exceed one year. This means that, under normal circumstances, a comprehensive calibration and test of the flammable gas detector is required annually to ensure its performance meets the relevant requirements.

Key Technical Requirements for Regular Calibration of Combustible Gas Detectors (Shenzhen ZhongNuo Testing Technology Co., Ltd.)
1. Power-On Self-Check Function: The instrument should have an automatic self-check function upon startup, with a manual self-check function for alarm components as well.
2. Specified Effective Detection Range: The effective detection range of the non-contact gas alarm instrument shall not be less than 20 m.
3. Alarm Value Settings: Specific alarm value settings are stipulated by the standard for different gases.
For example, the oxygen deficiency alarm setting is 19.5% VOL, and the oxygen-rich alarm setting is 23.5% VOL (refer to GB 8958-2006 "Operation Procedures for Oxygen Deficiency Hazardous Operations" 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-level alarm settings for toxic and harmful gases are determined based on OEL (Occupational Exposure Limit) or IDLH (Immediate Danger to Life and Health).
4. Error and Repetition: The standard sets clear requirements for the instrument's indication error, drift, and repeatability. For example, the indication error for flammable gases, toxic and harmful gases, and oxygen should be no more than 5% FS, 5% FS, and 2% FS respectively within the normal test range of the instrument's full scale.
5. Calibration and Interfaces: The instrument should be easy to calibrate, with set-up calibration programs and corresponding interfaces to ensure the accuracy of its measurement results.
6. Explosion-proof Performance: Equipment used in explosive environments must have explosion-proof performance in compliance with relevant regulations and obtain an explosion-proof certification.
7. Audio-Visual Alarm Devices: The audio-visual alarm devices of the alarm should meet specific visibility and sound pressure level requirements to ensure effective notification of 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 cutting off power supply or initiating the exhaust system, etc.
9. Power Requirements: Specific requirements are outlined for power supply voltage, continuous operating time, etc., for battery-powered and non-battery-powered instruments.
10. Other performance requirements: Including specifications for bearing, response time, full-range indication error, high-speed airflow, long-term stability, insulation withstand voltage, temperature, constant humidity and heat, electromagnetic interference resistance, steam interference resistance, vibration and drop resistance, and functionality.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proof, gas alarm, and toxic gas detection equipment for regular calibration, measurement, and certification services. We hold the necessary qualifications to assist clients in addressing fire and explosion prevention issues.