Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, certification, and measurement services for equipment such as gas alarms, combustible gas detectors, and toxic and harmful gas detectors for various locations. We offer nationwide services to address electrical safety and explosion-proof fire prevention issues for our clients, contributing to safe production.
Gas Detector Alarm Calibrator 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 of 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 per the regulations.
Occupational Health Standards for Toxic Gas Devices in Workplaces (GBZ/T223-2009), Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be performed regularly according to the manufacturer's specified time and procedures.
Section 3.4 of the "Code for the Use of Combustible Gas Detectors and Alarms" (SY6503-2000) stipulates: Combustible gas detectors and alarms for installation and use shall have measurement instruments manufactured by an institution recognized for their**explosion-proof performance**.

Primary Technical Requirements for Regular Calibration of Combustible Gas Detectors (Shenzhen ZhongNuo Testing Technology Co., Ltd.)
1. Self-check Function upon Power-On: The instrument should have an automatic self-check function when powered on, and a manual self-check function should be set for alarm components.
2. Specify the effective detection distance: The effective detection distance of the non-contact gas alarm instrument shall not be less than 20 m.
3. Alarm Value Settings: The standard specifies specific alarm value settings for different gases.
For example, the oxygen deficiency alarm setting is 19.5% VOL, and the oxygen enrichment 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 flammable 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 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, and calibration programs and corresponding interfaces should be set up to ensure the accuracy of its measurement results.
6. Explosion-proof Performance: Instruments used in explosive environments must possess explosion-proof performance in compliance with relevant regulations and obtain an explosion-proof certification.
7. Sound and Light Alarm Device: The sound and light alarm device of the alarm should meet specific visibility and sound pressure level requirements to ensure effective alerting 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 an exhaust system, etc.
9. Power Supply Requirements: Specific requirements are outlined for the supply voltage, continuous operating time, etc., for battery-powered and non-battery-powered instruments.
10. Additional Performance Requirements: Includes specifications for azimuth, response time, full-scale indication error, high-speed airflow, long-term stability, insulation withstand voltage, temperature, constant humidity and heat, resistance to electromagnetic interference, resistance to steam interference, vibration and shock, and functionality.

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

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 with a 60% span set point is approximately the full-scale. The uncertainty of the standard gas generating gas is not significant (%), and the standard substance for the gas standard substance should be greater than ±1%. The flow value error of the repeatability dilution device should not be greater than 0.%. The concentration unit of the gas standard substance should be converted to match the measuring unit of the inspected instrument when in use.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party institution specializing in electrical safety, electrical explosion-proofing, gas alarm systems, and toxic and harmful gas alarm instruments, offering regular inspections, metrological measurements, and calibration services. We are licensed to help customers address fire and explosion prevention issues.