Campbell Scientific 227-L Delmhorst Cylindrical Soil Moisture Block - Manual (Page 13)

227 Delmhorst Cylindrical Soil Moisture Block
7. Operation
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
7.1 Wiring
The 227 schematic is shown in FIGURE 7-1. The capacitors block galvanic
action due to the differences in potential between the datalogger earth ground
and the electrodes in the block. Such current flow would cause rapid block
deterioration.
The 227 uses a single-ended analog channel. TABLE 7-1 shows the datalogger
wiring.
Voltage
Excitation
Signal
Ground
Shield
FIGURE 7-1. 227 schematic
TABLE 7-1. 227 Wiring
Color
Function
CR10(X),
CR500, CR510
21X, CR7, CR23X CR800, CR850,
CR1000, CR3000,
CR5000, CR9000(X)
Black Excitation Switched Voltage
Excitation
Switched Voltage
Excitation Switched Voltage
Excitation
Red Signal Single-ended Channel Single-ended Channel Single-ended Channel
White Signal Ground AG
Clear Shield G
7