Sensor Placement (1-Color Mode ); Sensor Placement (2-Color Mode ) - RayTek MARATHON FA Operating Instructions Manual

Sensor Location
4.5 Sensor Placement (1‐Color Mode)
Optical head placement for one‐color temperature measurements is more critical than two‐color
measurements. The sensor must have a clear view of the target. There can be no obstructions on the
lens, window, or in the atmosphere. The distance from the target can be anywhere beyond the
minimum requirements, as long as the target completely fills the field of view. The following figure
illustrates proper placement when using the one‐color mode.
best good incorrect
Target greater than spot size
Target equal to spot size
Target smaller than spot size
Figure 10: Proper Sensor Placement in 1‐Color Mode
4.6 Sensor Placement (2‐Color Mode)
The following figure shows head placement under various conditions where two‐color temperature
measurements can be taken. Note, however, that if the sensor signal is reduced more than 95%
(including emissivity and obscuration of the target), the sensor accuracy also degrades.
14 Marathon Series FA/FR