Soil Testing Instruments

The Volume Change Gauge illustrated works on the principle of reversing the direction of flow when the limit of the volume change scale is reached. The number of cycles with the volume of fluid handled in each cycle provides the total volume change, whereas the sensitivity is governed by the dia of the polythene tube used. The sensitive volume change gauge has realized sensitivity of 0.003 ml/mm with the 6 ml volume of fluid per cycle. The apparatus consists of a volume measuring polythene tube running along both sides of a scale and connected at both ends to two mercury traps. These traps are connected to flow reversal valves through a manifold. The length of the polythene tube is enough to measure 6 ml volume of fluid per cycle. A small pallet of mercury is introduced in the circuit to be used as a cursor, and the movement of pallet is measured. The unit is tested to a pressure of 20bar (20 kg/cm2) and is designed for wall mounting.