The Voluvessel is used to determine in-place density of soil when testing compacted earth fills. The unit is a water-filled, calibrated vessel fitted with a hand-operated pump to pressurize the chamber. A thin, flexible membrane on the bottom displaces under pressure to fill a void. Using the base plate as a template, a hole is dug in the surface and the excavated soil is retained as a specimen. To determine the volume of the hole, the Voluvessel is mounted on the plate, the membrane (balloon) is pumped into the hole, and fluid displacement from the vessel is noted. In-place density is computed easily by dividing weight of the retained soil by the measured volume of the hole. A portion of the retained specimen is used to determine moisture content. This method is not suitable for very soft, easily deformed soils or in a hole which will not maintain constant volume. Water volume is read from the double-graduated scale on the high-strength clear plastic cylinder. Graduations are .00025ft³ or 7cm³.
Selection of Voluvessel model is determined by top-size of soil particles. 1/20ft³ HM-66 model is used for soils with 1/2in (13mm) maximum particle size and 1/13ft³ HM-67 model is for soils with particle size up to 1in (25mm). Each unit includes double-graduated cylinder, base plate, pressure/ vacuum pump assembly with quick-coupler, ten balloons, and an integral gauge for controlling pressure during calibration and testing. Extra Balloons are available in packs of ten. MA-26 Aqua-Check for moisture determinations and HMA-8 In-Place Density Accessory Kit are recommended optional accessories.