Densitometry by kk sahu

Introduction
Definiation
Principle
Fundamental of dencitometry
Types
transmission dencitometry
reflection dencitometry
combination dencitometry
Application
Bibliography

1. densitometry By KAUSHAL KUMAR SAHU Assistant Professor (Ad Hoc) Department of Biotechnology Govt. Digvijay Autonomous P. G. College Raj-Nandgaon ( C. G. )

2. contents Introduction Definiation Principle Fundamental of dencitometry Types transmission dencitometry reflection dencitometry combination dencitometry Application Bibliography

3. INTRODUCTION:- Densitometer is a tool used for measuring the optical density of a material. Such as photographic negative. In pressroom for printing work. To calculate and display the density color value it measure.

4. Definition:- Densitometer is a device that measure the degree of darkness (the optical density) of a photographic or semitransparent material.

5. Principle:- It is measurement of optical density in light sensitive material due to expose of light. Optical density result of darkness developed picture & number of darkness in a given area. Density measured by decrease in amount of light which shines through transparent film called absorptiometry. D MAX & D MIN refers maximum and minimum density recorded in the material.

6. Fundamental of densitometry:- Described by Beer and Lambert. Lamberts law-Amount of light absorbed is proportional to the thickness of absorbing material . Beers law-Amount of light absorbed by material is proportional to concentration of absorbing solution.

7. Types:- Mainly 3 types of densitometer are found:- 1) Transmission densitometer 2) Reflection densitometer 3) Combination densitometer

8. Transmission densitometer:- Measured the amount of light transmitted through a transparent material. Used to determine the opacity for diffferent areas of an original transparency. Example-Ihara T500 transmission densitometer, X-Rite 361T tabletop transmission densitometer. This will give reading for D min , the clear or unexpected film area and D max the darkest exposed black area of the film.

9. EXAMPLES:- X-RITE 361T Tabletop transmission densitometer Ihara T500 transmission densitometer

10. REFLECTION DENSTOMETER:- Measure the amount of light being reflected from a surface Reflection reading are also used to calculate total dot gain, error, gragness and other characteristics in printed pieces. Used in the pressroom area, Measure the Solid Ink Densities. Example-IQ 200 reflection densitometer, Model 428 color reflection densitometer.

11. IQ 200 Reflection densitometer

12. Combination Densitometer:- Measure both reflection and transmission densities. Examples- RT 120 Techkon Betacolour 54 xpress X- Rite

13. How density is measured? Density  is the mass of an object divided by its volume.  Density  often has units of grams per cubic centimeter (g/cm 3 ). Remember, grams is a mass and cubic centimeters is a volume.

14. APPLICATION:- Print media Photography Bone densitometry is most accurate and quickest process to determine osteoporosis in patient. Single beam gamma densitometer is used to measure the average void fraction in a small diameter stainless steel pipe under critical flow condition.

15. bibliography:- http://en.m.wikipedia.org/wiki/Densitometry. http:www.google.co.in= ncbi+ e:book + densitometer. NCBI E. book – Densitometry Textbook of quantitative chemistry (NCBI) E. book- Webster J.G Medical instrumentation, Application and Design, Boston, Houghton Miffin, Company- 1978.