Model 65 English Instruction Sheet
Page
6
Optical Resolution
Optical resolution (also called "Field of View" or "Distance-to-
Spot-Size Ratio") is the ratio of the thermometer’s distance from
the object’s surface to the size of the area measured ("spot
size"). The closer the thermometer is to the object, the smaller
the spot size. The laser spot size does not indicate the measured
spot size. (See "Laser Offset.")
The thermometer has an 8:1 optical resolution:
1
8
aab02f.eps
Distance
200 mm
(8 in)
400 mm
(16 in)
600 mm
(24 in)
800 mm
(32 in)
Spot Size
25 mm
(1 in)
50 mm
(2 in)
75 mm
(3 in)
100 mm
(4 in)
The minimum spot size is 25 mm (1 in), which occurs at a
distance of 200 mm (8 in) from the object. You cannot measure a
smaller spot size by getting closer.
The temperature displayed is an average temperature within the
spot size. Hot spots can be missed if the spot size is too large.
Get as close as possible but no closer than 200 mm (8 in).
Laser Offset
The laser beam is offset 18 mm (0.75 in) from the focal lens.
Choose a sampling spot large enough to include the laser offset.
Surface Temperatures
The thermometer measures the first surface it detects, even a
glass cover, dust, or fog. Make sure the object is not obstructed.
