Alcohol thermometer is an instrument used to measure temperature, commonly employed in photographic darkrooms, laboratories, and chemical processing areas. Unlike mercury thermometers, alcohol thermometers are inexpensive, lightweight, and less toxic, though generally less precise. They are ideal for monitoring the temperature of developing solutions, fixers, and other chemical baths, helping photographers maintain consistent processing conditions. Proper temperature control is essential for achieving accurate exposure, consistent development, and high-quality photographic results. Alcohol thermometers remain a practical and safe tool in many traditional and educational photographic workflows.