Uncoil the thermistor string and place it in the installation medium. For installations in which the string will be in contact with soil, rock, etc., take care to prevent damage to the cable and sensor. The termination assembly at the end of the string is made with a 1/4-20 x 1/2” deep threaded hole in it. This allows for a weight or cord/rope to be attached for assisting with the installation. The maximum pulling force that can safely be applied to the string is 20 lb.
3:
Figure 3: Model 3810A-3 End Terminator
Communications: RS-485, half-duplex
Baud Rate: 115200
Power: 12.0V ± 20% @ 1.2mA/sensor
2.3Model 8020-38 RS-485 to TTL/USB Converter
geokon makes the Model 8020-38 Addressable Bus Converter for connecting addressable strings to personal computers, readouts, dataloggers, and programmable logic controllers. The converter acts as a bridge using the TTL or USB protocols between readers and the geokon RS-485-enabled sensor strings.
For more information, please refer to the Model 8020-38 instruction manual.
4:
Figure 4: Model 8020-38 RS-485 to TTL/USB Converter
Note: The datalogger you use must have the appropriate port available.
Figure 4: Wiring of Datalogger without built-in RS-485 Conversion
nIf your datalogger does not have built-in RS-485 communications, connect the wiring using the diagram below.
nIf your datalogger has built-in RS-485 communications, connect the wiring using the diagram in the figure below.
5:
Figure 5: Wiring of Datalogger with built-in RS-485 Conversion