Reliability of suction table measurements

Abstract

The curve of hydrical retention is a key parameter of the soils behaviour that describes its capacity to retain water. Numerous experimental devices can be used to obtain this curve such as sucking table. It allows to apply a sucking on soil samples. When applying different sucking and measuring each time soil water capacity, we obtain a part of retention curve. Some air bubbles hidden in the hydraulic circuit of this measuring device can generate high errors of measure. We have implemented an electronic box called vacuometer. It is fitted with a pressure sensor and displays the sucking made by the table at the sensor level to ensure that the sucking at one extremity of the hydraulic circuit is correctly transmitted to the soil sample. When recording in continuous flow the sucking transmitted to the sample, this device relies on the measures realized. The quality reference of the laboratory is matched with it and the methods used are reliable.