A practical method for calibrating NTC thermistors
The Cave Pearl Project describes a thermistor calibration achievable by people who don’t have access to lab equipment with an accuracy better than ±0.15°C.
This method is particularly suitable for the 10k NTC on their 2-module data logger, handling them in a way that is easy to standardize for batch processing (ie: at the classroom scale).
We use brackets to keep the loggers completely submerged because the thermal conductivity of the water around the housing is required or the two sensors would diverge. The target range of 0-40°C used here covers moderate environments including the underwater and underground locations we typically deploy into. This method is unique in that it uses the freeze process rather than melting ice for the 0°C data point.
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