Densitometer

A densitometer is a device that measures the degree of darkness (the optical density) of a photographic or semitransparent material or of a reflecting surface. The densitometer is basically a light source aimed at a photoelectric cell. It determines the density of a sample placed between the light source and the photoelectric cell from differences in the readings. Modern densitometers have the same components, but also have electronic integrated circuitry for better reading.

Some modern types of German manufacture are capable of both types of measurements selectable by a switch. They are used in film photography to measure densities of negatives with the switch in the "T" (Transmission) position and the saturation of a resulting print in the "R" position. Such measurements enable the photographer to choose the right photo paper and the correct exposure, obviating experiments with test strips. Once the papers and darkroom have been calibrated, the first print from a previously measured negative is a success at once.

Industrial Tomography Systems (ITS) has collaborated with a leading European dredging contractor to develop their radiation and gamma free Dens-itometer based upon Electrical resistance Tomography. The system utilises electrical conductivity, to provide a greener, simpler, more cost effective alternative to conventional nuclear based systems. ITS pipe based sensors provide real time visual data on the processes occurring within the pipe.

The environmentally friendly Dens-itometer is making waves in the dredging and mining sector, as it can take measurements independent of flow regime and obtain readings of materials which are neutrally buoyant. The Dens-itometer has been tested on slurry conveying with 100,000s of tonnes of materials having been processed and delivering data consistent with gamma densitometers. It has also been deployed in food processing as a basis for measuring solids content in pipelines.

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