METER TEROS 12 Manual de usuario
TEROS 12
i
TABLE OF CONTENTS
1. Introduction..............................................................................................1
2. Operation ...................................................................................................2
2.1 Installation.................................................................................................2
2.2 Connecting.................................................................................................7
2.2.1 Connect to METER Data Logger.........................................................7
2.2.2 Connect to a Non-METER Logger ......................................................8
2.3 Communication..........................................................................................9
3. System....................................................................................................... 10
3.1 Specifications ..........................................................................................10
3.2 Components.............................................................................................13
3.3 Theory ......................................................................................................14
3.3.1 Volumetric Water Content ...............................................................14
3.3.2 Temperature....................................................................................15
3.3.3 Electrical Conductivity ....................................................................15
3.3.4 Converting Bulk EC to Pore EC.........................................................15
3.3.5 Pore Water Versus Saturation Extract EC ........................................16
4. Service....................................................................................................... 18
4.1 Calibrations..............................................................................................18
4.1.1 Mineral Soils...................................................................................18
4.1.2 Soilless Media.................................................................................18
4.1.3 Apparent Dielectric Permittivity......................................................19
4.2 Cleaning ...................................................................................................19
4.3 Troubleshooting........................................................................................19
18225-01
4.26.2018
ii
TEROS 12
4.4 Customer Support....................................................................................20
4.5 Terms and Conditions...............................................................................21
References .................................................................................................... 22
Index ................................................................................................................. 23
iii
1
TEROS 12
1. INTRODUCTION
Thank you for choosing the TEROS 12 Soil Moisture and Electrical Conductivity (EC) and
Temperature sensor.
The TEROS 12 sensor is designed to be installed in mineral soils, many types of growing
media, and other porous materials. This manual guides the customer through the sensor
features and describes how to use the sensor successfully.
TEROS 12 APPLICATIONS
• Volumetric water content (VWC) measurement
• Soil/substrate water balance
• Irrigation management
• Soil EC measurement
• Soil/substrate temperature measurement
• Solute/fertilizer movement
Prior to use, verify the TEROS 12 arrived in good condition. METER recommends testing the
sensors with the data logging device and software before going to the field.
2
OPERATION
2. OPERATION
Please read all instructions before operating the TEROS 12 to ensure it performs to its full
potential.
SAFETY PRECAUTIONS
METER sensors are built to the highest standards. Misuse, improper protection, or improper
installation may damage the sensor and possibly void the manufacturer’s warranty. Before
integrating the TEROS 12 into a system, follow the recommended installation instructions
and have the proper protections in place to safeguard sensors from damage. If installing
sensors in a lightning-prone area with a grounded data logger, see the application note
Lightning surge and grounding practices.
2.1 INSTALLATION
Follow the steps listed in Table 1 to set up the TEROS 12 and start collecting data. For more
detailed installation information consult the TEROS Sensors Best Practices Installation Guide.
Table 1 Installation
Tools Needed
Auger or Shovel
Secure Mounting Location for Data Logger and Cable
Optional Tool
Borehole Installation Tool
jack
cradle
carriage
shaft
actuator
lever
flashlight
TEROS
sensor
3
TEROS 12
Table 1 Installation (continued)
Preparation
Determine Best Installation Method
There are several methods for installing soil moisture sensors. These methods
are described in Table 2.
Avoid Putting any Metal in Between the Sensor and the Ferrite Core
Any metal located between the sensor and the ferrite core can interfere with
the TEROS 12 VWC measurement.
Check Sensor Functionality
Plug the sensor into the data logger (Section2.2) to make sure the sensor is
operating as expected.
Conduct System Check
Verify all sensors read within expected ranges. To validate both sensor
function and logger functionality, take a sensor measurement in air and
water. The TEROS 12 will read ~0.70 m3/m3in water and a slightly negative
value in air.
Installation
There are several methods for installing soil moisture sensors (Table 2). Keys to
a good installation and collecting good soil moisture data are described below.
Create Hole
Avoid interferring objects. If the TEROS 12 is installed near large metal objects
they can affect the sensor function and distort readings. Avoid large objects
like roots or rocks that could potentially bend the needles.
Auger or trench a hole to the desired sensor installation depth and direction
according to the installation method desired.
Insert Sensor
ATTENTION! Minimize air gaps around the sensor. Air gaps around the sensor
needles will result in low readings of soil moisture.
1. Load the TEROS 12 using the Borehole Installation Tool (BIT).
NOTE: The BIT provides a significant amount of mechanical advantage. See
Table2 for instruction on installing the TEROS 12 without the BIT.
2. Lower the tool into the hole or trench with the back of the tool supported
by the far wall.
3. Pull the tool lever to activate the jack and insert the sensor into the sidewall.
WARNING: When installing sensors in rocky soils, use care to avoide bending sensor needles.
The soil closest to the sensor has the strongest inuence on readings. It is ideal
to install the sensor in the native soil to get accurate soil moisture readings.
4
OPERATION
Table 1 Installation (continued)
Installation
(continued)
Sensor orientation. When the TEROS 12 sensor is installed, it may be
positioned in any direction (needles aligned horizontally or vertically). However,
installing the sensors with the needles in a horizontal position (as shown
below) will provide the least restriction to water ow through soil because the
water will ow through the soil directly to the needles.
Sensor body vertical and needles horizontal
Because of the shape of the sensor electromagnetic eld, installing the
sensor with the body oriented vertically will integrate more soil depth into
the soil moisture measurement. Installing the sensor with the body oriented
horizontally (on its side) will provide measurements at a more discreet depth.
See Measurement volume of METER volumetric water content sensors for
more information on sensor measurement volume.
Backll the Hole
Return soil to the hole, packing the soil back to its native bulk density.
Do not hit the ferrite core as this could potentially pull the sensor out of the soil.
Connect to Logger
Connect the 3.5-mm stereo plug connector into a stereo port on METER
data logger.
METER data loggers will automatically recognize TEROS sensors.
Use ZENTRA Utility software (Section2.2) to congure desired measurement
intervals and verify proper sensor identication by the logger.
Click SCAN in ZENTRA Utility to verify the TEROS 12 is active and providing
reasonable readings based on soild conditions.
Verify that these readings are reasonable based on soil conditions.
To connect to a non-METER data logger, refer to the TEROS 12 Integrator Guide.
5
TEROS 12
Table 1 Installation (continued)
Installation
(continued)
Secure and Protect Cables
Secure and protect cables with PVC casing or exible conduit to protect
against damage from rodents or driving over sensor cables.
Secure Excess Cable
To prevent loose cabling from being inadvertently snagged or tripped over,
gather and secure excess cable to the mounting mast in one or more places.
Tie excess vertical cable to the data logger mast to ensure cable weight does
not cause sensor to unplug.
Relieve Cable Strain
To relieve strain on the connections, leave the cables a little loose between the
logger and the closest secured point on the mast. This will allow for thermal
expansion and contraction of the cable without potentially pulling the stereo
connection out of the logger.
ERROR
OK
TEST
(–)
(+)
(–)
(+)
(–)
(+)
(+)
(–)
(+)
(–)
P1 P2 P3 P4 P5 P6
Securing excess cable
Table 2 contains brief descriptions for typical installation methods. Each has its own
advantages and disadvantages. For more information about which installation method
is best for specific applications, please see the TEROS 12 Installation Guide or contact
Customer Support.
6
OPERATION
Table 2 Installation methods
Borehole
This method uses the Borehole
Installation Tool (Table 1) that
allows a prole of soil moisture
sensors to be installed at
different depths within a single
augered borehole. A 10-cm (4-in)
borehole is augered vertically at
the measurement location. The
Borehole Installation Tool is then
used to install the sensors in the
sidewall of the borehole.
NOTE: The borehole method
requiresspecialized installation
toolavailable from METER ifinstalling
at depths greater than50cm.
Advantage
Minimizes soil
disturbance at
measurement
site.
Disadvantage
Requires a
specialized
installation
tool that can
be rented from
METER.
Trench
The trench installation method is
best for shallow installations (less
than 40 cm). This requires digging
a trench with a shovel, excavator,
etc.The trench needs to be dug to
the depth of the deepest installed
sensor. 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 then carefully backlled to
preserve the bulk density of the
soil and to avoid dislodging the
installed sensor by accidentally
snagging the ferrite core.
Advantage
Does not
require
specialized
equipment.
Disadvantage
Large soil
disturbance at
measurement
site.
Potentially
large
excavation
effort.
Tabla de contenidos
Otros manuales de Accesorios de METER
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METER TEROS 11 Manual de usuario
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METER ATMOS 14 Manual de usuario
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METER TEROS VERIFICATION CLIP Manual de usuario
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METER TEROS 21 Manual de usuario
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METER PHYTOS 31 Manual de usuario
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