Campbell Scientific 109-L Temperature Probe - Manual (Page 17)

Model 109 Temperature Probe
FIGURE 7-2. 109 and 41303-5A Radiation Shield on a CM200 Series
Crossarm
The 109 is held in the 41303-5A radiation shield by a mounting clamp at the
bottom (FIGURE 7-2). Loosen the mounting clamp screws, and insert the
probe through the clamp. Tighten the screws to secure the sensor and route the
sensor cable to the instrument enclosure. Secure the cable to the tripod or
tower using cable ties.
7.4 Water Temperature Installation
109 probes can be submerged to 15 m (50 ft) or 21 psi. The 109 is not
weighted, so a weighting system should be added, or the probe secured to a
submerged object such as a piling.
7.5 Soil Temperature Installation
The 109 tends to measure the average temperature over its length, so burying
the probe such that the measurement tip is horizontal to the soil surface at the
desired depth is usually preferred. The maximum burial depth for soil that
could become saturated with water is dictated by the maximum water pressure
allowed for the sensor, which is 21 psi.
One or two coils of cable should also be buried in a shallow installation. Burial
of some cable mitigates the effect of solar heating of the above ground cable on
the temperature measurement.
Placement of the cable inside a rugged conduit may be necessary for long cable
runs, especially in locations subject to digging, mowing, traffic, use of power
tools, or lightning strikes.
41303-5A
109
Tripod Mast
or Tower Leg
CM200 Series Crossarm
9