Hobo MX2306, Руководство пользователя

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HOBO MX Soil Moisture (MX2306) and MX Soil Moisture and Temperature (MX2307) Data Logger Manual
1 ‐ 508 ‐ 759 ‐ 9500 (U.S. and International) 8 www.onsetcomp.com
1 ‐ 800 ‐ LOGGERS (U.S. only)
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. With the verification clip attached, the
readings should be in the range of 0.35 to 0.42 m
3
/m
3
.
Refer to the TEROS verification clip documentation for
more information. 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 ~0.64
m
3
/m
3
in water (sensor fully submerged in water to 1 cm
up cable) and slightly negative in air. Use HOBOconnect 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.

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.

Use conduit to protect the cable against damage from
animals, lawn mowers, exposure to chemicals, etc.

Secure any loose cables with cable ties.
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. If using the temperature sensor for soil temperature, insert
that into the side of the hole, at least 2 cm (1 inch) from the
soil moisture sensor and ferrite core.
4. Secure the cable(s) and install conduit before backfilling the
hole.
5. Carefully return the soil to the hole, packing it back to its
native bulk density. Do not hit the ferrite core as this could
pull the sensor from the soil.
6. If using the MX2307 logger for air temperature, a solar
radiation shield is required if the temperature sensor will be
in sunlight at any time. (See Accessories)
Deploying and Mounting the Logger
Follow these guidelines when deploying the logger:

Mount the logger so the sensor cable is not being pulled.
Leave about 5 cm (2 inches) of drip loop in the cable
where it comes out of the logger to prevent water from
entering the logger housing.

Use the included large screws or cable ties to mount
the logger via the mounting holes. Use the screws to
attach the logger to a wall or flat surface. Use the
cable ties to affix the logger to a PVC pipe or mast.
Protecting the Logger
Note: Static electricity may cause the logger to stop logging.
The logger has been tested to 8 KV, but avoid electrostatic
discharge by grounding yourself to protect the logger. For more
information, search for “static discharge” on onsetcomp.com.
Drip Loop