Irrometer LT-12 Low Tension Soil Moisture Meter with Service Unit Kit - Accurate Water Tension Measurement for Soil, Peat, Bark, Sand, Perlite & Vermiculite | Ideal for Agriculture, Gardening, Greenhouse & Hydroponics

The IRROMETER operates on the tensiometer principle, which measures soil water tension. Soil water tension is the energy (vacuum) applied to the soil by the plant as it draws in water for nutrition. This force is measured in centibars (cb) or kilopascals (kPa) of tension with a high reading indicating the dry end of the scale and a low reading indicating the wet end of the scale. The IRROMETER instrument consists of a sealed, fluid filled tube that is equipped with a porous ceramic tip and a special vacuum gauge. They are installed in the ground with the tips placed at desired root zone depths. As the soil dries (increasing tension), fluid is drawn out of the instrument. This reduces the fluid volume in the IRROMETER, thus creating a partial vacuum which is registered on the gauge. The drier the soil, the higher the gauge reading. An irrigation application or rainfall event reverses this action. As water flows back into the soil (and the IRROMETER), tension is relieved in the soil and the instrument, resulting in a lower gauge reading (lower tension). In effect, the instrument is indicating how hard the roots are working. Due to the IRROMETER’s unique principle of operation, no calibrations are necessary under normal operating conditions for different soil types. A gauge reading of 15 cb (kPa) indicates that the roots are extracting the same amount of moisture whether the crop is planted in sandy soil or non-soil growing media. APPLICATIONS: Model LT IRROMETERS can be used for manual measurement and tracking of soil moisture status in coarse sandy soils and growing media. When equipped with optional electronic output and data logging equipment, measurement and tracking can be done automatically. The low tension vacuum gauge on this model can be replaced with electronic measurement options, or automatic switching devices which can activate peripheral equipment at desired soil water tension levels.