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 at various locations. We hold the necessary qualifications to serve nationwide, addressing all sorts of electrical safety and explosion-proof fire prevention issues for our clients, and contributing to safe production.
Regular Inspection Items for Environmental Gas Detection and Alarm Instruments in Workplace Operations:
Alarm sound and light (if applicable)
2. Low response value
3. Indication Error (for Gas Detectors/Gas Detector Alarms)
4. Instrument Drift (in portable instruments)
5. Alarm Error (for Gas Detection Alarm/ Gas Alarm)
6. Pump Suction Instrument Gas Sampling Distance and Flow Rate (for Pump Suction Instruments)
7. Power Supply (for battery-powered instruments)
8. Response Time
9. Status Indicator (with Wireless Communication Function)

Regulatory and Methodical Content for Regular Flammable Gas Detector Alarms Inspection
Annual inspections of the probes for commercial and industrial alarms are conducted regularly, primarily checking for the accuracy of the alarms' readings, repeatability, drift, and response time to ensure compliance with standards. Additionally, the suitability of the alarm installation location and any interference from other equipment are examined.

Primary Technical Requirements for Regular Calibration of Combustible Gas Detectors (Shenzhen ZhongNuo Inspection Technology Co., Ltd.)
1. Self-check function upon startup: The instrument should have an automatic self-check function when turned on, and the alarm components should also be equipped with a manual self-check option.
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 hypoxia alarm setting is 19.5%VOL, and the hyperoxia alarm setting is 23.5%VOL (refer to GB 8958—2006 "Operation Procedures for Hazardous Work in Oxygen Deficient Conditions" and GB 30871—2022 "Special Operation Specifications for Chemical Hazardous Goods 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, with set calibration procedures and corresponding interfaces to ensure the accuracy of its measurement results.
6. Explosion-proof Performance: Equipment for explosive environments must have explosion-proof performance in compliance 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 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 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: Including specifications for direction, response time, full-scale indication error, high-speed airflow, long-term stability, insulation withstand voltage performance, temperature, constant humidity and heat, resistance to electromagnetic interference, resistance to steam interference, vibration and shock, and functional requirements.

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: the verification cycle of the instrument generally should not exceed one year. If there is any doubt about the measurement data of the instrument, 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 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 Unit (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 the "Regulations for the Use of Combustible Gas Detectors" (SY6503-2000) stipulates that the installation and use of combustible gas detectors should have measurement instruments manufactured by an institution recognized for their **measuring** and **explosion-proof** performance.
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 calibrations. We provide certification services to address fire and explosion prevention issues for clients.