Campbell Scientific SI-111 (IRR-P) Precision Infrared Radiometer - Manual (Page 8)

SI-111 Precision Infrared Radiometer
3. Installation
The field of view for infrared sensors is calculated based on the geometry of
the sensor and lens. However, optical and atmospheric scatter and unwanted
reflections from outside the field of view may influence the measurement.
Under typical conditions, 95 to 98 percent of the IR signal is from the field of
view and 2 to 5 percent is from the area surrounding the field of view. If the
target surface is small, for example a single leaf, try to mount the sensor close
enough that the surface extends beyond the field of view.
Remove green cap from the SI-111 before mounting to a
crossarm, mast, or user-supplied support. NOTE
The SI-111 is often mounted to a CM202, CM204, or CM206 crossarm, a
tripod or tower mast, or a user-supplied pole via a CM220 right angle mount
(see FIGURE 3-1) or CM230 adjustable inclination mount. The CM230 allows
the sensor to be pointed at the surface of interest. When using the CM230, fix
the declination of the sensor by tightening the U-bolt that mounts on the mast
or crossarm. The inclination is then adjusted with the other U-bolt and nuts
(see FIGURE 3-2). A hole threaded for a standard tripod camera mount screw
(1/4 inch diameter; 20 threads per inch) can be used to mount the sensor to a
user-supplied support.
FIGURE 3-1. SI-111 mounted onto a CM204 crossarm via the CM220
FIGURE 3-2. SI-111 mounted onto a CM204 crossarm via the CM230
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