RAD BOARDS
Terms
undefined, object
copy deck
- How do you store film?
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* temp no greater than 68-70
* humidity - 40-60%
* stored on end - NOT flat
* if stored flat=pres. marks - Film is protected frm the following to prevent inc. density and fog...
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1. radiation
2. Fumes
3. Outdating
4. Light - Handling film
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* Pressure marks-stored flat
* static
* crinkle/half moom marks - Static caused by...
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* static buildup on tray
* static buildup loading bench
* low humidity in darkrm
* sliding film frm tray -should be placed - Half moon / crescent marks
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* bending over fingernail when hlding
* other rough handling -
Intensifying screens -
Base of film or backing -
*made of polyester
*mounted inside cassette - prs - dbl emulsion film
- Supercoat - Emulsion - Adhesive - Base - Adhesive - Emulsion - Supercoat
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Intensifying screens
Reflectv Layer -
*between base and actv layer
*reflects light frm crystals toward film
*increasing speed - Intensifying screen makeup
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Protectv layer
Phosphor layer
Reflective layer / absorbing
Base -
Instensifying screens
Actv layer - Phosphor -
*adheres to base
*phosphors glow with visible lght when struck by radiation
*phosphor size decrease - resolution increases - Resolution is measured in...
- * line pairs per mm
- What is a resolution grid?
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resolution quality control test -
it is radiographed so that the image can be evaluated -
Intensifying screen
Protectv layer - *thin coating on top of avtc layer to avoid scratches and other damage
- Screen speed (sensativity)
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*Phosphor used
*Phosphor size - lrg, fast
*Phosphor layer thickness - thicker, faster
*efficiency or reflctv layer - more eff, faster
*yellow dye in actv layer - yellow absorbs some phosphors light and reduces speed
*conversion efficiency-ability of phosphors to absorb xray energy and it convert it to visible light rays; higher conversions-faster screens