Campbell Scientific HMP50 Temperature and Relative Humidity Sensor - Manual (Page 7)

HMP50 Temperature and Relative Humidity Probe
3. Installation
3.1 Siting
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 where grass does
not grow, the natural earth surface. 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 measurement heights:
1.5 m +/- 1.0 m (AASC)
1.25 – 2.0 m (WMO)
2.0 m (EPA)
2.0 m and 10.0 m temperature difference (EPA)
See Section 9 for a list of references that discuss temperature and relative
humidity sensors.
3.2 Mounting and Assembly
Pull off the yellow shipping cap (see Figure 1).
The HMP50 must be housed inside a solar radiation shield when used in the
field. The 41303-5A 6-Plate Radiation Shield (Figures 2 and 3) mounts to a
tripod mast, UT10 tower leg, or CM202, CM204, or CM206 crossarm. The
HMP50 is held within the 41303-5A by a mounting clamp (Figure 3).
The UT6P 6-plate Radiation Shield mounts to a UT10, UT20, or UT30 tower
with the UT018 horizontal mounting arm.
The black outer jacket of the cable is Santoprene ® rubber. This
compound was chosen for its resistance to temperature extremes,
moisture, and UV degradation. However, this jacket will
support combustion in air. It is rated as slow burning when
tested according to U.L. 94 H.B. and will pass FMVSS302.
Local fire codes may preclude its use inside buildings.
NOTE
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