For measuring the developer temperature, which device is recommended?

• A. Mercury thermometer
• B. Built-in thermometer in the processor
• C. Alcohol thermometer
• D. External digital thermometer

Answer: (B)

Measuring the developer temperature correctly is essential because development time and film contrast depend on the bath being at the right temperature. The best choice is the built-in thermometer in the processor because it directly reads the temperature of the development solution and is integrated with the machine’s control system. This gives an accurate, real-time reading and allows automatic adjustments to keep the bath at the correct temperature.

Mercury thermometers are old and hazardous, and not ideal for the fast, repeated checks required in a processing room. Alcohol thermometers share similar drawbacks and can be less stable in this environment. An external digital thermometer could work, but readings may lag or be affected by placement, and it won’t automatically control the processor. The built-in sensor is designed for this purpose, providing reliable, immediate feedback to maintain consistent processing.