RXW TEROS-12 Soil Moisture EC Temp Sensor (RXW-T12-xxx) Manual
1-800-LOGGERS
5
www.onsetcomp.com
sensor and push it into to the side of the undisturbed soil. Look
down the hole and make sure it is firmly seated. You can also
consider attaching the sensor to PVC piping or similar material
to aid in placing the sensor. You can then use the PVC as a lever
to assist with pushing the sensor into the undisturbed soil.
Trench Installation Method
This method is best for shallow installations at less than 40 cm
(15.7 inches). This requires digging a trench with a shovel,
excavator, or other tool to the depth of the deepest installed
sensor (if installing more than one in the measurement
location). For deep installations, this may require a large trench.
The sensor is then installed carefully by hand into the
undisturbed soil of the trench sidewall. The trench is carefully
backfilled to preserve the bulk density of the soil and avoid
dislodging the installed sensor by accidentally snagging the
ferrite core.
Sensor Installation Guidelines
Before installing the sensor, follow these guidelines:
•
Test the sensor functionality and accuracy using the TEROS
verification clip. Refer to the TEROS verification clip
documentation for details on operation and expected
readings. If you do not have a verification clip, you can
perform a rough check of sensor functionality in air and
water. The sensor will produce readings of ~0.70 m
3
/m
3
in
water and ~0.003 m
3
/m
3
in air. Use HOBOlink to export or
view the data for your test.
•
When creating the hole to install the sensor, avoid
interfering objects. Installation near large metal objects
can affect the sensor function and distort readings. Large
objects like roots or rocks could potentially bend the
needles.
•
The sensor may be positioned in any direction. However,
there is less restriction to water flow when the sensor
body is placed in a vertical position as shown below. A
vertical position will also integrate more soil depth into
the soil moisture measurement. Installing the sensor with
the sensor body in a horizontal position will provide
measurements at a more discreet depth.
•
Do not touch the sensor needles with an ungloved hand or
bring them in contact with any source of oil or other
nonconducting residue. If the sensor needles are
contaminated with oils from contact with skin or another
source, follow the instructions in the
Maintenance
section
for cleaning the needles before installing the sensor.
•
Avoid any metal located between the sensor and the
ferrite core because it can interfere with VWC
measurements.
•
When installing sensors in rocky soils, use care to avoid
bending sensor needles.
•
Minimize air gaps around the sensor. Air gaps around the
sensor needles will result in low readings of soil moisture.
•
When backfilling the hole, be careful not to snag the
ferrite core on the sensor cable.
•
Secure the sensor cable to the mounting pole or tripod
with cable ties.
•
Use conduit to protect the cable against damage from
animals, lawn mowers, exposure to chemicals, etc.
Sensor Installation Instructions
1.
Auger or dig a hole to the desired sensor depth.
2.
Carefully insert the sensor in the hole and push the sensor
so that the needles are inserted into the undisturbed side of
the soil. Check that the sensor is firmly seated.
3.
Secure the cable to the mounting pole or tripod and install
flexible conduit before backfilling the hole.
4.
Carefully return the soil to the hole, packing it back to its
native bulk density. Do not hit the ferrite core as this could
potentially pull the sensor out of the soil.
Mounting and Positioning the Mote
•
Mount the mote to a mast or pipe using cable ties or affix
the mote to a wooden post or flat surface with screws.
Insert the cable ties or screws through the holes on the
mounting tabs.
•
Consider using plastic poles such as PVC to mount the
mote as certain types of metal could decrease signal
strength.
•
Make sure the mote remains in a vertical position once it
is placed in its deployment location for optimal network
communications.
•
Make sure the mote door is closed, with both latches fully
locked to ensure a watertight seal.
•
Consider using a 3/16 inch padlock to restrict access to the
mote. With the mote door closed, hook a padlock through
the eyelet on the right side of the door and lock it.
•
Position the mote towards the sun, making sure the solar
panel is oriented so that it receives optimal sunlight
throughout each season. It may be necessary to
periodically adjust the mote position as the path of the
sunlight changes throughout the year or if tree and leaf
growth alters the amount of sunlight reaching the solar
panel.
•
Make sure the mote is mounted a minimum of 1.8 m (6 ft)
from the ground or vegetation to help maximize distance
and signal strength.