High-resolution digital borehole thermometer calibrations and tests

We designed, built, calibrated, and tested high-resolution (sub-mK) digital down-hole thermometer probes for measuring temperature in boreholes in polar ice sheets. Because a digital sensor takes its measurement system down the hole, environmental influences on the long cable and on surface components do not degrade signal quality. Data include (a) calibration characteristics to ~1 mK from 2 different types of sensors, i.e. thermistors, and thin-film platinum resistance devices, at intervals of 5 deg C, in the range [0, -50 deg C], and (b) temperature-vs-depth logs at depth intervals of approximately 0.1 meters, collected between Dec.25 2001 and Jan 2, 2002, in the fluid-filled Siple Dome main ice corehole A (1004 meters deep, S81deg 39.5', W148deg 48.7') and to 145 meters depth in a fluid-filled tube in a nearby shallow hole L at Siple Dome, West Antarctica, suitable for sensor intercomparisons between digital tools, and between digital and analogue tools.