This Article is about: How to choose the correct IR Window and how many for your application.
The way to think about it when designing where/how to install the IR windows is what inspections will be required and can those be made with the IR window and IR camera (Ti camera) combination you plan on using for the inspection. The size of the IR window chosen, distance to target, type of IR camera, FOV (Field of View) of the camera, and how it fits against the IR window can all play a part. This can mean using some combination of 2, 3, 4 inch IR windows to “cover” the intended inspection points. It can be a tradeoff of cost and inspection time when deciding if larger IR windows and more IR windows are required. If using a Fluke Ti camera one can do a final check after installation of the IR window by setting the camera to IR fusion mode at 50% visible and 50% IR and seeing if the inspection points are visible.
These Field of View (FOV) calculations are based on best practices used during infrared inspections and serve as a guide when choosing IR Window sizes and locations. Please note that the illustrations represent achievable FOV at a distance of 30.48 cm (12 in) to target. Additional FOV calculations at various distances to target are given in the tables below. Actual FOV can vary based upon equipment layout (phase barriers, internal compartments, etc.). Be sure to verify IR Window position before drilling holes for installation. For illustration purposes, only horizontal FOV is shown. Adjusting the position of the thermal imager allows the overall FOV to be achieved in all directions—360 degrees.