Equitensiometer (Soil Water Potential)

quitensiometer FT3505.20 measures matric soil water potential. This is defined as the amount of work that must be done per unit quantity of pure water in order to transport reversibly and isothermally an infinitesimal quantity of water; identical in composition to the soil water, from a pool at the elevation and the external gas pressure of the point under consideration, to the soil water. If the specified quantity is volume, the potential is referred to as pressure (Pascal). Matric soil water potential is the main component of total soil water potential. In a not salty soil the total water potential is equal to the matric water potential. There are important differences between water content and water potential. The water content describes the amount of water in a soil, but not the availability of the water for plants. Plants would grow in a sand soil with 10% vol./vol. very well. But in a clay soil with the same water content, most plants would not survive because of dryout. Therefore, studies on soil water-plant-relationship will need the water availability, and this is the water potential. In comparison with known methods the Equitensiometer has the following advantages:

• Wide measuring range: 0 to -1500 kPa (0 to -15 bar)

• Highly accurate: error<5 kPa (5%)

• Absolutely maintenance free, without any of familiar tensiometer problems

• Independent measurements on soil properties
  Easy operation

• Suitable for outdoor use