#29: IRt/c can measure obliquely
Often, an area needs to be temperature monitored, but because of space limitations, the IRt/c cannot be placed to view the target area squarely. In such situations the IRt/c can be angled obliquely to view the target area. The field-of-view then becomes elliptical instead of circular, and the IRt/c averages the temperature it sees.
To apply this method, be sure to estimate the size of the field-of-view footprint, and confirm that the IRt/c is measuring the area you wish to measure.