5
PHYTOS 31
Ground (bare)
Analog output (orange)
Power (brown)
Figure 3 pigtail wiring
NOTE: LWS (predecessor to pHYTOS 31) may have the older Decagon wiring scheme where the power supply is white,
the analog is red, and the bare wire is ground.
Excitation
H
Analog in
Data Logger
Ground
L
Power
(brown)
Analog output
(orange)
Ground
(bare)
Figure 4 Wiring diagram
NOTE: The acceptable range of excitation voltages is from 2.5 to 5.0 VDC.
If the PHYTOS 31 cable has a standard stereo plug connector and needs to be connected to a
non-METER data logger, use one of the following two options.
Option 1
1. Clip off the stereo plug connector on the sensor cable.
2. Strip and tin the wires.
3. Wire it directly into the data logger.
This option has the advantage of creating a direct connection and minimizes the chance of
the sensor becoming unplugged. However, it then cannot be easily used in the future with a
METER readout unit or data logger.
Option 2
Obtain an adapter cable from METER.
The adapter cable has a connector for the stereo plug connector on one end and three wires
(or pigtail adapter) for connection to a data logger on the other end. The stripped and tinned
adapter cable wires have the same termination as in
: the brown wire is excitation,
the orange is output, and the bare wire is ground.
NOTE: Secure the stereo plug connector to the pigtail adapter connections using adhesive-line heat shrink to ensure
the sensor does not become disconnected during use.
