Capillary meter
A capillary meter is a device used to determine the water content of a soil sample with the suction tension set . In practice, the application range extends up to 0.7 bar or 7 mWS and theoretically up to 1 bar.
functionality
There is a porous plate between the soil sample and the adjustable U-tube, which is used to apply the suction voltage. If a suction voltage is applied, a state of equilibrium is established after some time in which water from the soil sample flows through the porous plate into the U-tube (drainage) or vice versa, if the suction voltage applied is lower than the soil suction voltage (irrigation). If a state of equilibrium has now established itself, the water content can be determined and the process can be repeated with a changed applied suction tension in order to obtain a suction tension-water content relationship ( water tension curve ).