Campbell Scientific CS506 Fuel Moisture Sensor - Manual (Page 8)

CS506 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 CS506 output is essentially a square wave with an amplitude
of
±0.7 VDC. The frequency of the square wave output ranges from
approximately 31 to 58 kHz. Its output period ranges from 17 to 32 μs.
*Fuel moisture accuracy:
(with a new stick)
90% of all
range measurements rms error
0 to 10% ±1.25% ±0.74%
10 to 20% ±2.00% ±0.90%
20 to 30% ±3.40% ±1.94%
30 to 50% ±4.11% ±2.27%
Range: 0-50%
Power Supply: 5 VDC minimum to
18 VDC maximum
Enable voltage: off at 0 V (<1 VDC)
on at 5 V (>4 VDC maximum 18 VDC)
Current usage: 65 mA active/ 45 uA quiescent
Output signal: ±0.7 V square wave with an output frequency of
approximately 31 to 58 kHz.
Weight: <0.5 kg (<1 lb)
Dimensions
Dowel:
1.3 cm (1/2 in) diameter, 50.8 cm (20 in) long
Electronics: 10.2 x 6.4 x 1.9 cm (4 x 2.5 x 0.75 in)
*The above accuracy is a static accuracy derived at slow changing conditions
with experimental data for the CS505. See Appendix A for explanation of
accuracy.
3. Installation
As shown in Figure 3-1 and Figure 3-2, both the CS506 and CS205 install on
the 26817 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. The mounting bracket is
positioned so that the sensor will be approximately 12 in. (30 cm) above the
ground, and then secured by tightening the nuts on the U-bolts. Once the
bracket is installed, insert the CS506 electronics into the two spring clips. The
fuel moisture sensor (part number 26601) installs on the CS506 electronics
with the supplied Phillips-head screws. The CS205 fuel temperature stick is
inserted into the mounting stake’s compression fitting. The 107 temperature
2