Nuclear density gauges

Density Nuclear gauges are the norm for density measurement. Nuclear density instruments require nuclear handling permits in most countries. Note that there are now some types that use very low level sources that do not require nuclear licensing. Density gauges should be recalibrated regularly as they are subject to drifting. Small flow applications may be able to use a coriolis meter to measure both mass and percent solids with one instrument. 

On-Line Instrumentation Used in the Coal Preparation Industry. Ash monitors, nuclear density gauges, and pH monitors are the only on-line instruments currently used to measure process or material parameters in U.S. coal preparation plants. 

Nuclear density gauges are typically used as process control instruments to monitor the density of water-magnetite slurries used in the heavy medium cleaning circuits The instrument... 

The development status of process control instrumentation lags that of the quality control instruments significantly Nuclear density gauges function in the coal preparation plant environment The slurry concentration meter has application in the intermediate and fine sized coal cleaning circuits and needs to be tested in a preparation plant Other devices, such as ash monitors to control the operation of heavy media baths or jigs are not available and instruments developed for other process industries are not suitable for use in coal preparation plants Modeling studies of the various unit operations are required in order to ascertain the fundamental parameters required to automate the control of these systems Primary process control instrument needs include ash, sulfur, and moisture monitors secondary needs include an on-line washability and ash fusion measurement ... 

Interpret... the results of a sand cone and nuclear density gauge field density tests. (4)... 

First, the moisture and compaction level of the stabilised soil using novel binder was measured using a nuclear density gauge. Table 46 shows the in-situ density and moisture content at four different points of the trial pavement. 

A. Ligabue, S. P. A. Sauer, P. Lazzeretti, Gauge invariant calculations of nuclear magnetic shielding constants using the continuous transformation of the origin of the current density approach. 11. Density-functional and coupled cluster theory, J. Chem. Phys. 126 (2007) 154111. 

Radiation gauging pertains to the use of penetrating radiation, in particular as emitted from radionuclides or radioactive isotopes, for the measurement of particular properties of a material or system. Such properties may include density, thickness, mass, volume, composition, uniformity, etc. In addition to the use of nuclear radiation from radioisotopes instead of X-rays from machine generators, the other distinguishing difference from Radiography is that electronic detectors are employed instead of flhn to measure the transmitted or scattered radiation... 

T. Helgaker, P. Wilson, R. Amos, N. Handy, Nuclear shielding constants by density functional theory with gauge including atomic orbitals, J. Chem. Phys. 113 (2000) 2983-2989. 

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