The IRROMETER supplies soil moisture information by acting as a “dummy root.” It consists of a sealed, water-filled tube equipped with a porous, ceramic tip that is installed in the ground at desired root zone depths. In dry soil, water is drawn out of the instrument, reducing water volume in the IRROMETER, thus creating a partial vacuum, which is registered on the gauge. The drier the soil, the higher the reading. Irrigation reverses this action. The vacuum previously created in the tube by dry soil draws water from the now irrigated soil back into the instrument. This in turn results in a lower gauge reading. Two instruments are necessary for accurate assessment of available water at the root zone: one is set shallow, the other deep.
Model ’LT’ & ‘MLT’ - Low Tension
The “low tension” IRROMETER incorporates a replaceable “Quick-Flo” tip, and a sealed gauge which has a full scale of 0-40 kPa. Designed for situations where tensions above 30 kPa are rarely expected. Ideal for very coarse soils; for container-media (non-soil), which can be relatively dry at 10-15 kPa; or where rapidly changing soil water status needs to be observed. MLT is a miniature LT for small containers.