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Darkroom and Film Processing Rad Tech A – Week 9 Spring 2009.

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Presentation on theme: "Darkroom and Film Processing Rad Tech A – Week 9 Spring 2009."— Presentation transcript:

1 Darkroom and Film Processing Rad Tech A – Week 9 Spring 2009

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4 Darkrooms – Still Necessary? Darkrooms are necessary for manually fed processors and daylight processors. -Loading automatic film processor magazines. Necessary for conducting certain quality control tests (daily sensitometric strip).

5 Darkroom

6 Darkrooms 4 Basic Functions Number 1 Function Storage –Unexposed film

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8 DARKROOM FUNCTION # 2 Purpose of Film Processing Change silver halide crystals from film emulsion (after exposure to x-ray or light photons) to black metallic silver. Latent image (invisible until processed) is developed into a Manifest image. Improper or careless processing can cause poor diagnostic quality.

9 Manual Feed Processor

10 Hand Processing in the Early years Strong smell of chemicals Messy Time comsuming

11 1956 – first roller transport 6 minute processing time

12 Processing Time 3 minutes 90 seconds

13 Processing Film Table top Processors TABLE TOP PROCESSOR Can process as fast as 60 seconds

14 PROCSSING CHEMICALS Solutions are PRE- MIXED Solutions are PRE- MIXED Outside Company usually provides service- Outside Company usually provides service- Weekly or monthly Weekly or monthly Solutions should be replenished as necessary & changed regularly Solutions should be replenished as necessary & changed regularly Solutions must be monitored (Daily QC strip). Solutions must be monitored (Daily QC strip).

15 Replenishment tanks

16 TABLE TOP FILM DUPLICATOR to MAKE COPIES OF FILMS

17 WILL THIS WORK ????

18 Daylight Processor

19 Function # 3: Handling of Film

20 UNLOAD EXPOSED FILM

21 Pass Box

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23 LOAD CASSETTE

24 Function # 4: Film Identification Pt name Exam date & time Pt x-ray number Pt Birthday/DOB Rt or Lt marker Optional –Exam type –Dr. Name

25 FILM ID PRINTER Name of patient place on top Cassette is “flashed” with name – can be done before or after image is taken Must be done BEFORE PROCESSING FILM

26 AUTOMATIC PROCESSING TRANSPORTATION SYSTEM DEVELOPER FIXER WASHER DRYER REPLENISHMENT SYSTEM

27 Automatic Processor

28 Processor Chemistry Overview Developer – converts latent image into manifest image Fixer – clear the film of unexposed, undeveloped silver bromide crystals, promotes archival quality Wash – rid the film of residual chemicals

29 Developer Solution (6 Ingredients) 1.Reducing Agent: reduce exposed silver halide to black metallic silver -Hydroquinone (Blacks) -Phenidone (Grays) 2. Activator: softens gelatin, maintains alkaline pH (increase pH) -Sodium Carbonate

30 Developer Solution 3. Hardener: prevents damage to the film from over swelling of gelatin in automatic processors. -Gluteraldehyde 4. Preservative: Antioxidant that prevents oxidation of developer -Sodium Sulfite

31 Developer Solution 5. Restrainer: prevents chemical fog in new developer -Potassium Bromide 6. Solvent: dissolves & ionizes the developer chemicals -Water

32 Fixer Solution (5 Ingredients) 1.Clearing Agent: dissolves undeveloped silver halide -Ammonium Thiosulfate 2. Tanning Agent: shrinks, hardens, preserves emulsion -Aluminum Salt

33 Fixer Solution 3. Activator: neutralizes developer, maintains acidic pH (decrease pH) -Acetic Acid 4. Preservative: prevents oxidation, prolongs solution life -Sodium Sulfite 5. Solvent: dissolves other ingredients -Water

34 Wash Rid the film of residual chemicals Residual chemicals on the film will discolor radiograph over time. Cold water processors are less efficient in removing chemicals – Warm water processors much better. Agitation during wash process is essential

35 Fixer Retention (Not Washed Off)

36 Transport System Components Feed Tray Rollers (Different Assemblies): 1. Entrance 2. Deep Racks 3. Turnaround 4. Crossover 5. Squeegee 6. Dryer Receiving Bin

37 Transport System (Rollers) Turnaround Entrance Deep Racks Crossover Squeegee Dryer Feed Tray

38 Processor (Top View)

39 Replenishment System Main function: Keep solution tanks full and assure proper solution concentration. As film is introduced into processor, sensor initiates solution replenishment Right & wrong way to feed in film -Feed in along short edge

40 Transport System in Automatic Processors Conveys the film through different solutions (sections) by a series of rollers driven by gears, chains & sprockets. Done at a prescribed speed – determines length of time the film is in each solution

41 Temperature Regulation Main function: To control the temperature of each section of the processor. Developer – most important solution to regulate Usually between 92 degrees and 95 degrees Thermostatically controlled

42 Recirculation System Provides agitation necessary for uniform solution concentration

43 Wash & Dryer Systems Wash: Provide thorough removal of chemical solutions from the film. -Archival film quality Dryer: Removes water from film by blowing warm, dry air - Between 120 degrees & 130 degrees F.

44 Silver Recovery About ½ of the film’s silver remains in the emulsion after exposure & processing. Other ½ (unexposed silver) is removed from the film during fixing process. Silver is toxic to public water supply – must have proper disposal. Silver can be harvested from the fixer tank and recycled.

45 What is in the Darkroom?

46 Darkroom Contents Loading Bench Film Bin Film I.D. Printer Safelights Pass Box Light-tight Room Ample ventilation Warning Light outside room Lockable Door Wall Shielding if adjacent to x-ray room Walls painted with light color to reflect safelight

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48 Darkroom Equipment

49 SAFELIGHTS

50 Safe Light 15 Watts Red filter Must be 3-6 feet from counter top or feed tray of processor Used to be amber or orange filter

51 Darkroom Summary

52 Summary & Questions

53 X-ray Cassettes cross section review layers What are the 4 layers? Of FILM & SCREENS ?

54 Film cross section

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56 RTA LAB 2 Next Week : PROCESSING & SCREEN EXPOSURE IONIZING LAB INTENSIFYING SCREEN DARKROOM PROCESSING & CHEMISTRY COMPLETE IN CLASS WORKSHEET


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