Campbell Scientific 110PV Surface Temperature Probe - Manual (Page 15)

110PV Surface Temperature Probe
FIGURE 3-4. 110PV’s strain relief label
3.4 Submersion
The 110PV can be submerged to 50 ft. It must be adhered to a dry clean
surface before submerging. The probe’s adhesive mounting disc is not
intended for submersion. Therefore the 110PV must be mounted to the
measurement surface via a user-supplied method that is compatible with
submersion.
4. Wiring
Connections to Campbell Scientific dataloggers are given in Table 4-1. Most
CRBasic dataloggers can measure the 110PV using either a 4-wire half bridge
or 3-wire half bridge. The CR200(X) and Edlog dataloggers can only use a
3-wire half bridge. The 4-wire half bridge method is preferred because it
reduces cable errors (see Figures 2-2 and 2-3). The 4-wire half bridge method
requires two differential input channels and one voltage excitation channel.
The 3-wire half bridge method uses one single-ended input channel and one
voltage excitation channel.
Multiple probes can be connected to the same excitation channel. The number
of probes per excitation channel is physically limited by the number of lead
wires that can be inserted into a single voltage excitation terminal,
approximately six.
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