Evaluation of a low-cost temperature measurement system for environmental applications

Thermochron iButtons incorporate the latest in digital technology, making them smaller, less expensive, durable and potentially more reliable than many other temperature logging devices. The objective of this study was to test the accuracy of an inexpensive air temperature measurement system, composed of a Thermochron iButton and radiation shield. Sixty-one iButtons were subjected to a sequence of two water baths (0 degrees C and 24.9 degrees C) to assess the absolute accuracy of the sensors. Five solar radiation shields were tested in a greenhouse setting to evaluate the reduction in radiative heating. Significant differences (p < 0.05) were detected between instruments subsequent to both water-bath treatment analyses. The accuracy of the sensors was well within the manufacturer's stated specification of 1.0 degrees C with a collective temperature variance of +/- 0.21 degrees C. Temperature responses generated by the Thermochron iButtons in different radiation shields were consistent, but varied significantly (p < 0.05) from 28 to 44 degrees C based on diurnal temperature ranges. Results indicate that the Thermochron Mutton is an accurate, inexpensive alternative to more expensive temperature data-logging systems, and is well suited for obtaining quality spatially distributed data for hydrologic and water quality investigations. Copyright (c) 2005 John Wiley & Sons, Ltd.