Introduction
Fixed gas detectors are essential for monitoring hazardous gases in industrial environments such as petrochemical plants, power facilities, and chemical processing units. Proper installation ensures accurate detection of combustible and toxic gases, preventing accidents and ensuring compliance with safety standards. At Shanghai Gewei Electronic Safety Equipment Co., Ltd., we specialize in advanced gas detection systems, including our GDE, GDC, and GDA series detectors, which use high-performance sensors like infrared and catalytic types for reliable performance. However, common installation errors can compromise system effectiveness. This article outlines five frequent mistakes and provides practical steps to avoid them.
Mistake 1: Selecting the Wrong Gas Detection Principle
One prevalent error is choosing an unsuitable sensor type for the target gas and environment. For instance, using a catalytic combustion sensor in a high-humidity area may lead to false readings due to poisoning or corrosion, while infrared sensors perform better in such conditions but may not detect all gas types accurately.
Gas sensors convert gas concentrations into electrical signals, and common types include catalytic combustion, infrared, semiconductor, electrochemical, and photoionization (PID). Each has specific applications: catalytic for combustible gases in dry environments, infrared for long-life monitoring of hydrocarbons, and electrochemical for toxic gases like CO.
How to Avoid It
Assess the environment and gases present. For complex industrial settings like oil refineries, opt for versatile systems. Our GDE series fixed gas detectors use infrared and laser sensors with over 5 years lifespan and ±3% accuracy, suitable for harsh conditions. They support bus and point-to-point outputs, allowing easy integration. Always consult manufacturer specifications, such as those in GB15322 standards, to match the principle to the site requirements.
Mistake 2: Incorrect Placement of Detectors
Placing detectors in locations where gas accumulation is unlikely or where interference occurs reduces detection efficiency. For example, mounting too high for heavier-than-air gases like propane leads to delayed alerts, or near ventilation fans disperses gases before sensing.
Gas behavior varies: lighter gases like methane rise, while heavier ones settle low. Environmental factors such as airflow, temperature gradients, and obstacles must be considered to ensure sensors sample representative air.
How to Avoid It
Follow guidelines from standards like NFPA 72 or GB3836. Position detectors at 0.5-2 meters height for heavier gases and higher for lighter ones. In our GDC series, which use catalytic and infrared principles, the compact design with IP66 rating allows flexible mounting in zones 1 and 2 hazardous areas. Perform a site survey to map gas leak points and avoid dead zones. Integrate with our GM810/GM820 controllers for multi-point monitoring, ensuring coverage across large facilities like power plants or pipelines.
Mistake 3: Neglecting Calibration and Maintenance
Failing to calibrate sensors regularly causes drift, leading to inaccurate readings or false alarms. Sensors like catalytic types degrade over time due to exposure, with zero drift up to 2% every six months if unmaintained.
Maintenance intervals depend on the sensor: infrared sensors last longer than catalytic ones, but all require periodic checks for response time (T90 typically 20-25 seconds) and linearity.
How to Avoid It
Schedule calibrations every 3-6 months using certified gas mixtures. Our products feature automatic temperature compensation and zero-point calibration, simplifying the process. The GDA series, ideal for chemical and pharmaceutical plants, supports plug-and-play sensors with pre-calibration, reducing downtime. Use remote operation via infrared remotes without opening covers, and monitor via our IoT cloud platform with 4G/WiFi modules for real-time status from mobile apps. This ensures compliance and extends sensor life beyond 3-5 years.
Mistake 4: Inadequate Power Supply and Wiring
Insufficient power or poor wiring causes system failures, especially in remote or expansive installations. Detectors typically require DC 24V with ranges of 18-30V, and currents up to 100mA during alarms, but overloads from long cables exceed limits.
Wiring errors, like exceeding RS485 bus distances (max 1.5km), lead to signal loss, while ignoring explosion-proof requirements in hazardous zones risks ignition.
How to Avoid It
Use dedicated power supplies with backup batteries and calculate cable resistance (e.g., 4-20mA loops up to 600 ohms). Our GDE and GDC series include relay outputs for low/high alarms (2A at 30VDC) and 4-20mA signals programmable for fault states (e.g., 0-2mA for power failure). Employ explosion-proof conduits and ensure Exd IIC T6 certification. Pair with our GM8 series controllers, which use modular designs and automatic addressing for stable bus communication, supporting expansion without external protectors.
Mistake 5: Poor Integration with Alarm and Monitoring Systems
Isolated detectors without linkage to alarms or central systems delay response times. Without integration, alarms may not activate sirens, shutdowns, or notifications, rendering the setup ineffective in emergencies.
Modern systems require compatibility for outputs like relays, Modbus, or Ethernet to connect with SCADA or DCS.
How to Avoid It
Design the system with interoperability in mind. Our gas detectors support RS485, 4-20mA, and relay interfaces, compatible with our graphical display software and IoT cloud platform. The GM820 controller enables networking with external devices, forming scalable monitoring networks. Include voice-light alarms and I/O modules for automated responses, such as ventilation activation. Test the full chain during commissioning to verify end-to-end functionality.
Conclusion
Avoiding these installation mistakes enhances the reliability of fixed gas detectors in protecting workers and assets. By selecting appropriate sensors, strategic placement, regular maintenance, robust power setups, and seamless integration, systems perform optimally. Shanghai Gewei offers comprehensive solutions, including our durable GDE, GDC, and GDA series with anti-explosion designs for diverse industries. Contact us to ensure your gas detection installation meets the highest standards, backed by CCC and CPA certifications.