SBOS685C – APRIL 2014 – REVISED JULY 2015
Feature Description (continued)
7.3.2 Field of View and Angular Response
The TMP007 senses all radiation within a defined field of view (FOV). The FOV (or full-angle of θ) is defined as
2Φ. The TMP007 contains no optical elements, and thus senses all radiation within the hemisphere to the front of
the device. Figure 2 shows the angular dependence of the sensor response and the relative power for a circular
object that subtends a half angle of phi (Φ). Figure 19 defines the angle Φ in terms of object diameter and
distance. Figure 19 assumes that the object is well approximated as a plane that is perpendicular to the sensor
Figure 19. FOV Geometry Definition
In this case, the maximum contribution is from the portion of the object directly in front of the TMP007 (Φ = 0),
with the sensitivity per solid angle, dR/dΦ decreases as Φ increases. Approximately 50% of the energy sensed
by the TMP007 is within a FOV (θ) = 90°.
This discussion is for illustrative purposes only; in practice the angular response (dR/dΦ) of the TMP007 to the
object is affected by the object orientation, the number of objects, and the precise placement relative to the
TMP007. Figure 20 shows the thermopile sensor dimensions.
NOTE: Thermopile sensor is centered in the device.
Figure 20. Thermopile Sensor Dimensions
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