For precise and reliable results, the probe must be properly installed.
The smaller the pots, the greater the chance of error.
Important facts:
- The TEROS soil sensors measurement volume is 1010 ml. It is approximated as an ellipsoidal cylinder - see figure below for specific dimensions.
- Good soil-to-sensor contact is essential to getting quality soil moisture data. Foreign objects (that is not soil – e.g. pot’s plastic wall), and especially air gaps will influence the readings and reduce accuracy.
- The sensor should be installed at least 1 cm within the soil surface to avoid sensing the air above the soil (see figure below).
- Sensors need to be spaced far enough apart so that one sensor won't interfere with another's volume of influence (if using more than one sensor in a pot).
Thus, the proper way to install the sensor in the pot is (in a typical face down application):
- Locate the probe as much as possible in the center of the pot:
- Ensure there is at least 3 cm of soil below the tip of the sensor’s prongs (fork)
- Ensure the probe upper edge (cable start) is at least 1 cm below the soil surface
- Locate the probe as far as possible from the pot walls (at least 3 cm) - Make sure there is a good soil-sensor contact.
- Be consistent.
For more information about the sensor, address the official manual.
For more information about how to install soil moisture sensors, read more here.
