Information AboutDensitometry |
| CATEGORIES ABOUT DENSITOMETRY | |
| measurement | |
| optical metrology | |
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Densitometry is the quantitative Measurement of optic Density in light-sensitive materials, such as Photographic Film , due to exposure to Light . Optic Density is a result of the darkness of a developed picture and can be expressed absolutely as the number of dark spots (i.e., Silver Nitrate grains in developed films) in a given area, but usually it is a relative value, expressed in a Scale . Density is also the Logarithm of the inverse of Transparency . Since density is usually measured by the decrease in the amount of light which shines through a transparent film, it is also called Absorptiometry , the measure of Light Absorption through the medium. The corresponding measuring device is called a Densitometer or an Absorptiometer . According to the principle of operation of the densitometer, one can have:
Dual Energy X-ray Absorptiometry is used in Medicine to evaluate Calcium Bone density, which is altered in several diseases such as Osteopenia and Osteoporosis . Special devices have been developed and are in current use for clinical Diagnosis , called Bone Densitometers . EXTERNAL LINKS
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