Campbell Scientific CS505 Fuel Moisture Sensor - Manual (Page 6)

CS505 Fuel Moisture Sensor
the media surrounding the stainless steel strips. The dielectric constant is
predominantly dependent on the water content of the wood. Digital circuitry
scales the oscillation frequency to an appropriate range for measurement with a
datalogger. The CS505 output is essentially a square wave with an amplitude
of
±2.5 VDC. The frequency of the square wave output ranges from
approximately 600 to 1500 Hz.
*Fuel moisture accuracy:
(with a new stick)
90% of all
range measurements rms error
0 to 10% ±2% ±1.0%
10 to 20% ±3% ±1.5%
20 to 30% ±5% ±2.2%
30 to 50% ±6% ±2.4%
Range: 0-50%
Power Supply: 9 VDC minimum to
18 VDC maximum
Enable voltage: off at 0 V (<1 VDC)
on at 5 V (>1.5 VDC maximum 12 VDC)
Current usage: 70 mA active/ 10 uA quiescent
Output signal: ±2.5 V square wave with an output frequency of
approximately 600 to 1500 Hz.
Dimensions:
sensor:
1/2 inch dowel, 20 inch long
electronics: 4 x 2.5 x 0.75 inches
*The above accuracy is a static accuracy derived at slow changing conditions
with experimental data.
3. Installation
As shown in Figure 3-1 and Figure 3-2, both the CS505 and CS205 install on
the 10974 mounting stake. The probes install horizontally and should point
south in the northern hemisphere and north in the southern. The rack is
mounted above a representative forest-floor duff layer. The stake is carefully
hammered into the ground so that it is vertical. Don’t hammer on the spot-
welded clips that hold the CS505 electronics. Once the stake is installed,
insert the CS505 electronics into the two spring clips. The fuel moisture
sensor (part number 10824) installs on the CS505 electronics with the supplied
Phillips-head screws. The CS205 fuel temperature stick is inserted into the
mounting stake’s compression fitting. The 107 temperature probe is then
inserted into the CS205 stick. Tighten the compression fitting so that it
compresses the split wood and snugly holds the 107 probe.
2