Infrared Useful in Hazardous Plants
December 8, 2008
The presence of combustible gases in certain industrial environments creates a serious risk of explosions. Intrinsically safe devices prevent explosions in hazardous locations by limiting the energy and surface temperature of the device under normal operation, or when conditions arise that could become hazardous.
An infrared thermometer enables the user to recognize equipment malfunctions or process problems before they can affect the operational process or result in process downtime. The units are helpful for plant and equipment maintenance, and repair prevention.
Some infrared devices can be approved as intrinsically safe only after passing a rigorous process required by a recognized entity. Instruments that have PTB- and TÜV-certified hazard classes EEx ia IIC T4 and EEx ib IIC T4 approval can be used with a large number of different gases or easily flammable vapors. Raytek, Santa Cruz, Calif., now joined by Ircon Inc., also headquartered in Santa Cruz, Calif., have developed infrared units that meet strict hazard class requirements.
Certain models of the Raytek Thermalert TX have been certified by PTB as intrinsically safe according to hazard class EEx ib IIC T4. Series TX of the two-wire fixed online infrared sensors is designed for online temperature monitoring of machinery and plant processes. It has a 4 to 20 mA interface and can be remote-programmed via the Hart/RS232 interface using Windows software. The sensor measures temperatures over the range of 0.4 to 3,632°F (-18 to 2,000°C). All measuring data are displayed graphically and stored for subsequent evaluation.
The Ircon Modline 5 with explosionproof XP housing has been designed for special Modline 5R sensors and is certified AEx d IIB + H2. The compact housing ensures reliability in severe industrial environments and includes remote interface via the company's DPM, MSI or Modline 5 Modview software to access sensor settings.