A digital auto-recorder for measuring the drinking frequency of mice

An inexpensive, automatic digital recorder to measure the drinking frequency of mice was designed. When an animal licked the spout of the water bottle, it closed the path of the current of the amplifier input circuit and a module converted the closure signal into an electric pulse. A camera preset by a timer automatically photographed the counter which had accepted the pulse. The apparatus was inexpensive and estimated the drinking frequency of many mice individually and simultaneously. This system is applicable as a pulse-recorder to physical phenomena other than water intake.