Table 6-2: Relative dielectric permittivity specifications
CS650
CS655
Volumetric water content
Range
0% to 100%
Accuracy†
±1% (with soil specific calibration),
±3% (typical with factory VWC
model) where solution EC
< 3 dS/m
±1% (with soil specific calibration),
±3% (typical with factory VWC
model) where solution EC
< 10 dS/m
Precision‡
<0.05%
Electrical conductivity
Range solution EC
0 to 3 dS/m
0 to 8 dS/m
Range bulk EC
0 to 3 dS/m
0 to 8 dS/m
Accuracy†
±(5% of r 0.05 dS/m)
Precision‡
0.5% of bulk electrical conductivity (BEC)
Temperature
Range
–50 to 70 °C
Resolution
0.001 °C
Accuracy†
±0.1 °C (for typical soil temperatures
[0 to 40 °C] when sensor body is buried in soil),
±0.5 °C for full temperature range
Precision‡
±0.02 °C
Sensing volume*
7800 cm
3
3600 cm
3
*Sensing volume approximately 7.5 cm radius around each sensor rod and 4.5 cm beyond the end of the rods
†Accuracy specifications are based on laboratory measurements in a series of solutions with dielectric permittivities
ranging from 1 to 81 and solution electrical conductivities ranging from 0 to 3 dS/m.
‡Precision describes the repeatability of a measurement. It is determined for the CS650 by taking repeated
measurements in the same material. The precision of the CS650 is better than 0.05 % volumetric water content and
0.01 dS/m electrical conductivity.
CS650 and CS655 Water Content Reflectometers
9
