Inexpensive recording thermometer
A. P. Jackman, Robert Noble, H. J. Bonouvrie · Review of Scientific Instruments · 1977
Monitoring of water temperature is widespread, due to its importance as a water quality parameter. This paper describes a simple, accurate, and inexpensive recording temperature monitor based on a thermistor temperature sensor. A special resistance bridge circuit is incorporated whose output is extremely linear with temperature. The output of the bridge network is converted to a frequency signal which can be recorded on an inexpensive cassette recorder. The entire system, capable of recording up to 9 days’ data, is powered by two 6-V lead–acid motorcycle batteries.