The evaluation of a clinical thermometer for measuring developer temperature in automatic film processors

In medical imaging, the temperature of the developer solution in the film processor affects film speed (radiation dose), film contrast, and film base plus fog. The National Council on Radiation Protection and Measurement (NCRP) Report 99 on Quality Assurance, and the American College of Radiology (ACR) Mammography Quality Control Manual for Radiologic Technologists, indicate that the developer temperature should be within +/- 0.5 degree F (+/- 0.3 degree C) of that recommended by the manufacturer for the specific film/developer combination being used. The accuracy and repeatability of the thermometer is most important. This paper describes the requirements of a thermometer for measuring the temperature of the developer solution and suggests an inexpensive but accurate device for doing so.