Plant Monitoring with Thermography in Explosion Hazard Environments

Infrared cameras can perform wide-area monitoring of temperature trends. This is why they are very effective for early fire detection and continuous condition monitoring. Through the introduction of explosion-proof enclosures with pressure-proof encapsulation it is now possible to install temperature measuring infrared cameras in explosion hazard environments complying with the latest explosion protection standards.

Especially in ex-proof areas, safety is very important and relies on continuous condition monitoring. In chemical plants and refineries, temperature is an important factor for identifying critical conditions. But how can safety in big plants be reliably controlled through temperature? Conventional cameras cannot detect excessive heating in pumps, motors or valves; nor can they see fluid leaks. Temperature sensors do not provide enough significant information, because they provide only punctual measurement data with which large installations cannot be properly monitored. In contrast, temperature measuring infrared cameras can fulfill such tasks easily. However, it was not until recently that housings complying with the current Ex-proof standards, enabled the use of infrared cameras in these environments. This task could be accomplished only with the help of the ATEX-certified IRCamSafe Ex-AXC enclosures, which allows the operation of infrared cameras in explosion protection zones 1, 2, 21 and 22.

Monitoring Large Ex-proof Areas
The infrared systems already installed confirm that even large and irregularly shaped locations can be monitored successfully. For this, complete system-solutions are used that contain hardware and software including any number of infrared cameras. These cameras are located in such a way that all the areas to be monitored are fully covered. To enable the centralized management of such a complete system, each protective enclosure is equipped with an integrated electronic board. This board allows the camera to be connected directly to a network, either through Ethernet cable or a fiber optic cable. Of course, the electronic board, as all the other components of the enclosure, is also included in the ATEX certification so that no further re-certifications are required for the installation.

Continuous Analysis
During operation, the infrared cameras send their thermal images via the network to the IRMonitor central analysis software. To detect potentially hazardous situations, the software assigns every camera a specific plant area to be monitored (zones). Because each monitored zone can have different alarming requirements, a zone-specific analysis is configured. This can provide, for example, the verification that critical temperature thresholds are not exceeded or the monitoring of critical temperature trends in the field of view of the camera. The IRMonitor software also has special functions such as "template matching" to enable the correct positioning of the measurement areas, considerably minimizing the risk of false alarms.

If an alarm condition is detected, the system automatically activates an output signal that can be used to initialize counter measurements. Furthermore, a maximized live image of the affected area is shown in the software and it is also highlighted in the plan overview (Map View). This helps to determine the cause of the alarm and enables personnel in the control station to take decisions on the coordination of further action.

All Inclusive
The many advantages of thermography-based systems for wide-area monitoring make this kind of solution very interesting for many industries. With the launch of the ATEX certified IRCamSafe Ex-AXC enclosure, such systems can even be used in explosion hazardous areas. The certification of this enclosure includes all of its components so that no further re-certification is required for its installation, thereby saving time and money. This ex-proof enclosure contains all the components required for its installation and reliable operation and the installation effort is reduced to a minimum. This enables customers to carry out monitoring operations with a high degree of efficiency and reliability.

On the whole, GIT-SECURITY.com thinks that it is really worth taking a closer look to this system - it is innovative and effective.