METER TEROS 21 - Connecting the TEROS 21 Sensor

3
TEROS 21
Table 1 Installation (continued)
Field Installation
(continued)
Install Sensor
For shallow installation (less than ~30 cm), use a knife to remove a small sliver
of soil. Insert packed sensor into the channel.
For deep installation (greater than ~30 cm), use the native soil to make a slurry
with water. Lower sensor into the hole and ll with the slurry.
NOTE: Soils with high shrink-swell potential may pull away from the sensor as they dry
and disrupt measurements.
NOTE: Do not install the sensor with the body exposed above ground.
Connect to Logger
Leave at least 15 cm (6 in) of sensor cable beneath the soil before bringing the
cable to the surface. At least 10 cm (4 in) of cable should exit the sensor body
in a straight line before bending the cable.
Plug the sensor into the logger.
Use the data logger to make sure the sensor is reading properly.

Return soil to the hole, packing the soil back to its native bulk density.
2.2 CONNECTING
The TEROS 21 sensors work best with METER data loggers or ProCheck handheld readers.
1. Check data logger software and firmware versions to ensure they support
TEROS21 sensors (http://www.metergroup.com/teros21-support/).
Plug the stereo plug connector directly into one of the sensor ports.
2. Congure the logger port for TEROS 21 using the appropriate logger application.
The TEROS 21 sensors have a 5-m cable. Customers may purchase custom cable lengths
for an additional per-meter fee. If the cable needs to be extended, ensure to adequately
waterproof the cable splices to prevent a major failure point. Read Wire splicing and sealing
technique for soil moisture sensors for more information.
The sensor uses a 3.5-mm stereo plug connector (Figure1). Customers may purchase the
sensor with stripped and tinned wires (pigtail) for terminal connections for third-party data
loggers (Figure2). Refer to the individual third-party logger manual for details on wiring.
NOTE: The acceptable range of power voltages is from 3.9 to 15.0 VDC, with 12 VDC being the optimal voltage.
Ground
Data
Power
 3.5-mm stereo plug connector