Dongguan Combustible Gas Detector Inspection

Shenzhen Zhongnuo Testing Technology Co., Ltd. specializes in the calibration, verification, and measurement services for gas alarms, combustible gas detectors, toxic and harmful gas detectors, and other equipment in various locations. We hold the necessary qualifications to serve nationwide, providing solutions to electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
Standard for calibration and verification of flammable and toxic gas detectors:
GB/T 50493-2019 "Design Standard for Detection and Alarm Systems of Combustible and Toxic Gases in Petroleum and Chemical Industry"
GB12358-2006 General Technical Requirements for Environmental Gas Detection and Alarm Instruments in Workplace
JJG693-2011规程 for Inspection and Verification of Flammable Gas Detectors and Alarms

Gas Detector Alarm Calibration Specification Requirements
Regulation 5.5 of the "Regulation for Inspection and Verification of Combustible Gas Detectors" (JJG693-2011) states: The inspection cycle for combustible gas detection and alarm instruments: Generally, the inspection 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 inspection.
Section 3.5 of "Code for the Use of Combustible Gas Detection and Alarm Systems" (SY6503-2000) stipulates: Combustible gas detection and alarm systems in use shall be calibrated regularly as per regulations.
Occupational Health Service Establishment Code for Toxic Gas Devices (GBZ/T223-2009) Article 7.2.1 stipulates: Calibration of detection and alarm devices shall be carried out regularly in accordance with 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 should have measurement instruments manufactured by an institutionally recognized manufacturer and **explosion-proof performance**.

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 clean, with a uniform paint and plating finish, and free of peeling or rusting.
The instrument's connections are reliable, and all knobs or buttons should operate and control normally.
Logos and branding
Instrument name, model, manufacturer's name, date of manufacture, serial number, explosion-proof marking and number, as well as the manufacturing metrological instrument license mark and number for domestically manufactured instruments should be clear.

Key Technical Requirements for Regular Calibration of Flammable 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. 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 Setting: Specific alarm value settings are standardized for different gases.
For example, the oxygen deficiency alarm setpoint is 19.5%VOL, and the oxygen enrichment alarm setpoint is 23.5%VOL (refer to GB 8958-2006 "Operation Code for Oxygen Deficiency 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 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 Repeatability: The standard specifies clear requirements for the instruments' 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: Equipment for explosive environments should possess explosion-proof properties in accordance with relevant regulations and obtain an explosion-proof certification.
7. Audio-Visual Alarm Device: The alarm's audio-visual alarm device must meet visibility and sound pressure level requirements under specific conditions to ensure effective alerting of staff during emergencies.
8. Output Control Function: Instruments with output control functions should be able to activate the output control when an alarm signal is emitted, such as cutting off power or starting 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 requirements for direction, 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.
Shenzhen ZhongNuo Testing Technology Co., Ltd. is a third-party service provider specializing in electrical safety, electrical explosion prevention, gas alarms, and toxic and harmful gas detection instruments for regular calibration, measurement, and certification. We are qualified to assist clients in solving fire and explosion prevention issues.