INFRARED TRANSPARENT WINDOWS

In my personal experience scanning through three brands (Fluke, SqD Comet & IRISS), all work fine - see photos at left.  However, each has unique limitations to consider before installing.

• SIZE - The best option is the larger size.  It allows for more flexibility to scan the larger 13.8KV cabinets for example.  The camera can pivot 360° to see components above, below and at the sides.
• PLACEMENT - It is all about field of view... direct line-of-sight.  A "hot spot" can occur at every connection in a cabinet.  Install the windows so that the thermographer has a view of everything in the bucket.  Often, to attain that goal means installing more than one window.  
• SIGNAL LOSS - All three of the samples shown at the left of this page had a reduced signal coming through the IR Transparent material (should be called semi-transparent).  Some - such as the bottom window are less transparent than the rest.  As long as the thermographer is aware of the material & signal loss, the temps can be compensated-for by changing the emissivity.  The crystal clear lens of the SquareD HVirComet (middle IR photo) in my experience is nearly lossless, while the Fluke lost about 50% depending on the temp of the object being scanned (see hot motor at top left and the bottom IR photo).  And, this varied considerably with the temperature of the hot spot... meaning the emissivity value had to be changed as the temperature of the target changed - in order to get an accurate reading!