How to deploy the sensor

Sensor Installation

This section describes the intended handling of the sensor. Please follow the instructions closely.

For the installation the material specified below is required:

  • Sensor(s)
  • Bucket
  • Shovel or similar digging tool 
  • Water

Sensor Preconditioning

Before the sensor installation, the Watermark sensor needs a certain preconditioning in water. Once a sensor was out of the soil for two days or more, preconditioning should be performed again. This is done to improve sensor response during the first few irrigations. To correctly set up the sensor, the following steps should be completed:

During the soaking procedure the whole metal part of the sensor should be covered in water (see Figure 5).

Sensor Installation

For sensor installation, a hole of the required depth needs to be made. Its diameter should slightly exceed the sensor diameter (25mm/1”). Once the hole is prepared, the sensor can be placed.

To place the sensor at the desired depth, keep an eye on the marks you can see on the sensor (see next figure). If you know the required depth and want to calculate the number of marks that must be visible for the respective depths, see next figure.

The calculated depth is measured from the center of the watermark sensor to each mark on the shaft of the housing.

Example: If you intend to place the middle of the watermark sensor at 14 cm depth/5.5 inches, you need to make sure that the top mark is at soil level (0 visible marks above soil level). If your intention is to place the middle of the sensor at 6.5cm depth (minimal depth) the first mark should be at soil level and 5 additional marks should be visible.

If not desired differently, or not stated otherwise: place the sensors at 14 cm depth.

To finish the physical sensor placement, mud is produced by mixing field soil with water. The space around the sensor is then filled with the mud (see below figures). If necessary, some additional soil is added, so that the sensor can not wiggle anymore.

These general rules should be followed when installing a sensor into the ground:

  • The soil in the area surrounding the sensor should not be excessively compacted/hardened. This can be avoided by digging a hole large enough to easily fit the sensor.
  • The sensor must have full contact with the surrounding soil, this is very important to make sure the collected data is useful.

Figure 7

Figure 8

Space around the sensor is filled with a soil slurry

Sensor placed in a corn field

Sensor Removal

If you wish to remove the sensors from the ground, carefully remove them by excavating them. When advised to return them to Cital, see our Return Shipments page. 

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