Developer temperature test details: frequency and device?

• A. Daily; external thermometer; +/- 1°F
• B. Weekly; built-in thermometer; +/- 0.5°F
• C. Recommended by Manufacturer and done with a built-in thermometer into the processor, daily, +/- 0.5°F
• D. Monthly; external thermometer; +/- 0.5°F

Answer: (C)

Temperature control in the film processor directly impacts chemical activity and film density, so the best QA approach is to follow the manufacturer’s guidance and use the thermometer built into the processor. This in-situ measurement reflects the exact processing conditions, minimizing lag and placement error. Checking this daily keeps you in tune with any everyday fluctuations, preserving consistent image quality. The tight tolerance of +/- 0.5°F ensures the processor stays within a narrow range needed for reproducible results. Using an external thermometer can misrepresent the actual processing temperature and introduce delay, while less frequent testing risks missing drift that could affect film density and contrast.