Radiology, Vol 129, 509-514, Copyright © 1978 by Radiological Society of North America
A comparison of five methods for monitoring the precision of automated x-ray film processors
EL Nickoloff, F Leo and M Reese
Five different methods for preparing sensitometric strips used to monitor
the precision of automated film processors are compared. A method for
determining the sensitivity of each system to processor variations is
presented; the observed statistical variability is multiplied by the system
response to temperature or chemical changes. Pre-exposed sensitometric
strips required the use of accurate densitometers and stringent control
limits to be effective. X-ray exposed sensitometric strips demonstrated
large variations in the x-ray output (2 omega approximately equal to 8.0%)
over a period of one month. Some light sensitometers were capable of
detecting +/- 1.0 degrees F (+/- 0.6 degrees C) variations in developer
temperature in the processor and/or about 10.0 ml of chemical contamination
in the processor. Nevertheless, even the light sensitometers were
susceptible to problems, e.g. film emulsion selection, line voltage
variations, and latent image fading. Advantages and disadvantages of the
various sensitometric methods are discussed.
