Campbell Scientific 108-L Temperature Probe - Manual (Page 14)

Model 108 Temperature Probe
Variations:
• Temperature reported as °F – add a multiplier ( P37) of 1.8 and an
offset ( P34) of 32
• Ac mains noise filtering — see Section 8.3, Electrically Noisy
Environments
• Compensate for long cable lengths — see Section 8.4, Long Cable
Lengths
7.3 Air Temperature Installation
For air temperature measurements, sensors should be located over an open
level area at least 9 m (EPA) in diameter. The surface should be covered by
short grass or the natural earth surface where grass does not grow. Sensors
should be located at a distance of at least four times the height of any nearby
obstruction, and at least 30 m (EPA) from large paved areas. Sensors should
be protected from thermal radiation and adequately ventilated.
Standard air temperature measurement heights:
1.25 to 2.0 m (WMO)
2.0 m (EPA)
2.0 m and 10.0 m temperature difference (EPA)
When exposed to sunlight, the 108 should be housed in a 41303-5A or 41303-
5B six-plate solar radiation shield. The louvered construction of the shields
allows air to pass freely through, thereby keeping the probe at or near ambient
temperature. The white shields reflect solar radiation. The 41303-5A attaches
to a crossarm, mast, or user-supplied pipe with a 2.5 to 5.3 cm (1.0 to 2.1 inch)
outer diameter. The 41303-5B attaches to a CM500-series pole or a user-
supplied pole with a 5.1 cm (2.4 inch) outer diameter.
Tools required for installing on a tripod or tower:
• 1/2 inch open-end wrench
• small screwdriver provided with datalogger
• small Phillips screwdriver
• UV-resistant cable ties
• small pair of diagonal-cutting pliers
8