Processor Quality Control Problem Solving

1
Processor Quality Control Problem Solving

• Chapter 21

2
Processor Quality Control

• Process of Processor Quality Control
• Check the temperature of the developer by use of
  a thermometer.
• Check water temperature.
• Check fixer temperature.
• If developer temperature is within 0.5 of
  specifications produce and process the
  sensitometric strip.

3
Check Developer Temperature

• Proper development of the latent image is
  dependent upon
• Developer temperature
• Concentration of developer solution
• Time film spends in the developer
• Temperature must be to specifications

4
Check of Water Temperature

• If the water is too cold, it will be more costly
  to heat the developer to operating temperature.
  If water is too warm, the developer will over
  heat.

5
Check of Fixer Temperature

• The fixing of the image is dependent upon the
  fixer being within factory specification but is
  not as critical as developer temperature.

6
Expose Sensitometric Strip

• The Sensitometer produces highly reproducible
  step wedge images used to monitor the performance
  of the developer.
• Using film set aside for processor quality
  control, expose both sides of the film with the
  Sensitometer.

7
Process the Sensitometric Strip

• Always feed the film into the processor the same
  way and on the same side of the feed tray.
• Bromide drag and affect the image.

8
Read the Sensitometric Strip

• A Densitometer is used to read the optical
  density of the strip.
• Read an area of unexposed film to check the base
  plus fog (BF) of the image.
• Then read the Speed and Contrast Steps.

9
Read the Sensitometric Strip

• The amount of light passing through the image is
  the optical density of the image.
• Speed or Mid Density is the step closest a
  reading of 1.00 Base Fog or 1.20 OD
• Contrast or Density Deference is the deference
  between the steps closest to 0.25 Base Fog or
  0.45 and the step closest to 2.00 Base Fog
  or 2.20 OD.

10
Graph the Results on the Processor QC Chart

• The processor should be checked before x-rays are
  taken on the first patient.
• If a problem exists, it must be corrected before
  processing patient films.

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21.3 Processor QC Problem Solving

• Processor QC monitors the development of the
  film. These factors impact development
• Developer Temperature
• Time of Development
• Activity of the Developer
• Also the darkroom and film storage conditions
  will impact Processor QC.

12
Base Plus Fog

• Any unexposed area of the film can be tested to
  determine the Base Plus Fog exposure level.
• Base Plus Fog is the level of pre-existing
  exposure exposure above the blue tint of the base
  of the film.

13
Base Plus Fog

• Items that will impact the Base Plus Fog
  includes
• Condition of film storage after manufacture.
• Light integrity of the dark room
• The light spectrum from the safelight
• Temperature of the developer
• Contamination of the developer

14
Speed Index or Mid Density

• This is the step closest to 1.00 plus BF or 1.20
  Optical Density. It corresponds to the middle of
  the useful exposure level on x-ray film.
• Factors that will impact the Speed Index include
• Developer Temperature Low Temperature will
  produce lower speed.

15
Speed Index or Mid Density

• Developer Temperature High Temperature will
  produce increased speed.
• Fog level of the film Increased Base Fog will
  increase the Speed Index.
• Time spent in the developer Increased time at
  the correct temperature will increase speed.
• Activity of the developer under replenishment
  will lower the Speed Index

16
Speed Index or Mid Density

• Activity of the developer under replenishment
  will lower the Speed Index
• Over replenishment will result in increased Speed
  Index.
• Contaminated Developer If fixer gets into the
  developer, the developer will be contaminated.

17
Contrast or Density Difference

• Contrast Index is the difference between a step
  that produces a light shade of gray (0.25 O.D.
  BF) and the step that produces upper range of
  viewable light on an exposed film (2.00 BF)
• Step closest to 2.20 minus Step closest to 0.45
  equals the Contrast Index.

18
Contrast or Density Difference

• Factors that will affect the contrast level
  include
• Fog level on the film
• Developer Temperature
• Development Time
• Contamination of the developer

19
Processor QC limits

• The action level or results that should result in
  corrective steps being taken vary between
  national limits and those recommended by
  California.
• California recommends the tightest standards that
  will produce the most consistent image quality.

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Processor QC limits

• Developer Temperature 0.5 F (Ca) 1 to 2
  F.(US)
• BF 0.03 OD (California) 0.05 OD (US)
• Speed Index 0.10 OD (Ca.) 0.15 OD (US)
• Contrast Index 0.10 OD (Ca.) 0.15 OD (US)
• The California Standards are used in this course.

21
Monitoring Frequency

• Daily when patients will be x-rayed
• Check fresh chemical levels
• Check that water flowing into wash tank and tank
  is full
• Check drive gears for wear.
• Check developer temperature when heater begins to
  cycle.
• Clean work surface and feed tray of processor.

22
Monitoring Frequency

• Daily when patients will be x-rayed
• Clean cross over rollers or process two to three
  roller cleaning films.
• Perform Processor Sensitometry or QC
• Determine BF, Speed and Contrast Index
• Chart results
• Analyze results and take action as indicated.

23
Monitoring Frequency

• At close of business each day or shut down
• Raise cover of processor about two inches
• Drain wash tank
• Semi-annual and at startup tests
• Immersion time or Speed of Processor Drive
• Water Flow Rate

24
Chart 1

• Problem solving
• Start with developer temperature
• Then look at Base Fog
• Then look at Speed Index

25
Processor within Limits Chart 1

• With proper developer temperature, reasonable
  volume of films processed and proper rate of
  replenishment the processor should stay within
  limits.
• After cleaning the speed will increase due to
  fresh developer. This is normal.

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Processor within Limits Chart 1

• Trends can be monitored when the processor is
  within limits.
• Continued lower than normal speed index is a
  symptom of under replenishment. A slight increase
  in replenishment may be warranted

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Processor within Limits Chart 1

• If you are under replenishing the chemicals and
  the case volume drops, the developer may go bad.
• Continued high reading means over replenishing of
  the developer.

28
Chart 2

• Problem solving
• Start with developer temperature
• Then look at Base Fog
• Then look at Speed Index

29
Problem 1 Chart 2

• Symptoms
• BF and Speed are up
• Contrast is down
• Developer Temp normal
• Diagnosis
• Problem with dark room with safelight or light
  leak in darkroom.

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Problem 1 Chart 2

• Solutions
• Check bulb wattage in safelight
• Check for light leaks
• Check for damage to filter in safelight.
• Check fluorescent fixture for after glow.
• Move safelight

31
Chart 3

• Problem solving
• Start with developer temperature
• Then look at Base Fog
• Then look at Speed Index

32
Problem 2 Chart 3

• Symptoms
• Gradual decrease in Speed Index
• Temperature within limits
• BF within limits
• Diagnosis
• Low volume of films processed
• Under replenishment

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Problem 2 Chart 3

• Solutions
• Run two to three fresh 14x17 films or roller
  cleaning films each day through processor. Do Not
  run rejected films as they will contaminate the
  developer with residual fixer.

34
Problem 2 Chart 3

• Solutions
• Slightly increase the developer replenishment
  rate until the volume of cases increase.
• Check for low levels of chemical in processor
  tanks.

35
Chart 4

• Problem solving
• Start with developer temperature
• Then look at Base Fog
• Then look at Speed Index

36
Problem 3 Chart 4

• Symptoms
• Gradual rise in speed and contrast
• Sudden drop in Speed, Contrast and Developer
  temperature
• These are two separate but common problems.

37
Problem 3 Chart 4

• Symptoms Gradual rise in speed and contrast.
• Problem If the volume of x-ray films processed
  each day increases significantly, the developer
  will be over replenished.
• Solution If film processing volume remains high,
  reduce replenishment .

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Problem 3 Chart 4

• This is not typically recommended because a drop
  in film volume will quickly result in under
  replenishment.
• Other factors that can cause this increase
• a new box of control film that is a little
  faster. Change aim if speed changes with the new
  box of control film.

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Problem 3 Chart 4

• Other factors that can cause this increase
• a drop in the drive speed will cause the film to
  remain in the developer longer. This can be the
  result of a bad bearing, or roller or problem
  with the drive motor.
• Always check the developer temperature first.

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Problem 4 Chart 4

• Problem 2 Symptoms
• Drop in developer temperature, speed and
  contrast.
• Diagnosis Developer Temperature Control Problem
  or the test was done before the developer reached
  operating temperature.

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Problem 4 Chart 4

• Solutions
• If the developer temperature was checked before
  the strip was run, the problem would have been
  addressed without the need for the film.
• It is very important to know how long it takes
  the processor to warm up in the morning. Time
  varies from 20 to 45 minutes.

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Problem 4 Chart 4

• If some time has passed between the check of the
  developer temperature and processing the control
  strip, the following must be considered
• The developer thermostat, developer heater or
  fuse for the heater has failed.
• Most processor will have a light that blinks when
  the heater is on. If the light remains out, the
  heater is not working.

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Problem 4 Chart 4

• If the water coming into the processor is too
  cold, the developer heat controls will
• Fail prematurely because of excessive needs for
  heat.
• You will use more power to maintain the developer
  temperature.

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Chart 5

• Problem solving
• Start with developer temperature
• Then look at Base Fog
• Then look at Speed Index

45
Problem 5 Chart 5

• Problem Repeated increases in developer
  temperature, Speed Index and Contrast Index
• Solutions The developer temperature is
  controlled by the heater, thermostat and water
  temperature on most processors. The problem will
  generally be within these systems.

46
Problem 5 Chart 5

• If the water was not turned on, the developer
  will over heat.
• If the water was turned on but the water flow
  control valve is defective or clogged, the
  developer will over heat.
• Test control valve every six months
• Use a water filter to control mineral content of
  water.

47
Problem 5 Chart 5

• The thermostat may have failed closed resulting
  in the over temperature condition.
• The film may have been run with the processor set
  at the wrong speed and developer temperature.
• Medical facilities use extended processing for
  mammography to reduce radiation by increasing
  speed and improve contrast.

48
Problem 5 Chart 5

• IF the Speed Index, Contrast Index and Base Fog
  increased with normal developer temperature, the
  drive system is faulty.

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Chart 6

• Problem solving
• Start with developer temperature
• Then look at Base Fog
• Then look at Speed Index

50
Problem 6 Chart 6

• Symptoms Speed Index and Contrast Index
  continue to fail with normal developer
  temperature and processing speed. The processor
  is fine right after service.
• Solution The processor is under used due to very
  low exam volume.

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Problem 6 Chart 6

• The developer in the processor tanks will oxidize
  if fresh solutions are not added to the tank. As
  developer ages, it turns brown.
• The replenishing tanks should be air tight.
• To avoid this problem the following may be done

52
Problem 6 Chart 6

• Every other day or daily turn on the processor
  and run two or three 14 x 17 films to pump fresh
  chemicals into the tanks.
• When you turn on the processor check chemical
  levels in the tanks. Evaporation is also a
  problem when film volume is low.

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Problem 6 Chart 6

• Use flood replenishment to pump fresh chemicals
  into the tanks. Every few hours, fresh chemicals
  are pumped into the processor.
• This will maintain the proper chemical levels in
  the tanks and avoid chemical deposits on the
  rollers.

54
Water, Fixer and Q C

• Fixer Problems
• Contamination A very small amount of fixer
  getting into the developer will ruin or
  contaminate the developer.
• Improperly clearing of a film jam can cause this.
• Running rejected films to clean the rollers will
  contaminate the developer.
• Use new film or roller cleaning film.

55
Water, Fixer and Q C

• Fixer Problems Under replenishment
• If the replenishment of the fixer is too low,
  the film will jam in the wash tanks or dryer
  because of a lack of hardening of the emulsion.
• The films will not dry properly.
• The film will be easily scratched and will not
  last as long in the files.

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Other Processor QC Tests

• Water Flow Meter Accuracy Measure water flow
  into processor. Criteria 5 Done quarterly
• Processor Transport Time Measure time from when
  the leading edge of the film enters the processor
  until leading edge exits the dryer. Criteria
  3 Done annually

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Conclusions

• Processor Q C monitors the developer.
• Developer replenishment, temperature and time the
  films spend in the developer are critical to
  consistent image quality.

58
Processor Troubleshooting
Problem BF up BF Same MD up MD down DD down
Darkroom Fog X X X
Developer Temp Up X X X
Developer Concentration Too High X X X
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Processor Troubleshooting
Problem BF up BF Same MD up MD down DD down
Water Temperature Too High X X X
Developer Over- replenishment X X X
Developer Time Too Long X X X
60
Processor Troubleshooting
Problem BF up BF Same MD up MD down DD down
No Starter after processor service X X X
Developer Contaminated X X X
Expired Film X X X
61
Processor Troubleshooting
Problem BF up BF Same MD up MD down DD down
Developer Temperature too low X X X
Developer Concentration Too Low X X X
Under-replenishment X X X
62
Processor Troubleshooting
Problem BF up BF Same MD up MD down DD down
Oxidized or exhausted Developer X X X
Inadequate Starter X X X
Exhausted Fixer X X X