Evaluation of the Stevens HydraProbe Temperature Measurements from -30 to +40 Degrees Celsius
Soil temperature data down to -30° Celsius is becoming more and more relevant to climate studies. While environmental issues fuel the development and the widespread use of sophisticated environmental models, reliable input data is becoming essential for researchers and modelers. The soil temperature data collected by the HydraProbe can be used in climate studies in arctic regions, regional energy budget calculations, drought forecasting and heat fluxes. It is the intent of Stevens Water Monitoring Systems to provide the scientific community a reliable and cost-effective soil temperature sensor to suit the needs of environmental researchers.
Three prototype Stevens HydraProbes were modified to accurately measure soil temperatures from -30°C to +40°C. The three prototype sensors were placed in an environmental chamber capable of maintaining constant temperatures in the range of interest. Temperature measurements were obtain by the three Hydra Probes at various temperatures within the range and compared to that of a standard thermistor. The Pearson correlation coefficient (R2) was used to quantify the performance of the HydraProbe measurements in the selected range. The coefficient of variation (CV) and a 99% confidence interval were the statistical tools used to quantify the precision of the measurements. The R2 values were found to be 0.99943 and the precision under a normal 99% confidence interval (1<CV ) was +/- 0.26°C.
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