Relative density
A pycnometer (from Greek: πυκνός (puknos) meaning "dense"), also called pyknometer or specific gravity bottle, is a device used to determine the density of a liquid. A pycnometer is usually made of glass, with a close-fitting ground glass stopper with a capillary tube through it, so that air bubbles may escape from the apparatus. This device enables a liquid's density to be measured accurately by reference to an appropriate working fluid, such as water or mercury, using an analytical balance.
DM3 density meter
The DM3 weighs media (slurry) as it travels through a metered section of pipe using a patented, high resolution load cell. Using linear, direct sensing of mass per unit volume, measurement system within a reinforced rubber tube. This in-line section of pipe calculates % dry solids, wet density and wet or dry mass flow units. When coupled with compatible volumetric flow meters and processing units, this system gives a true value for density and mass flow. The DM3 is a bi-directional unit which allows media to flow continuously through either ends. "C" Clamps located within the DM3 allows the flow tube to withhold high levels of pressure encountered. The flow tube was designed to focus on the highest amount of accuracy, resolution, and least amount of weight without compromising mechanical stability and reliability. Because of the sensitivity of measurement provided by DM3, each unit must be programmed and calibrated to accommodate the variation in Earth's gravitational force.