The accuracy of miniature bead thermistors in the measurement of upper air temperature

Abstract

A laboratory study was made of the errors of miniature bead thermistors of 5, 10, and 15 mils nominal diameter when used for the measurement of atmospheric temperature. Although the study was primarily concerned with the errors of the thermistors when used in Meteorological rocket soundings between about 70 km and 30 km altitude the results are also valid for other applications of these thermistors at all altitudes down to sea level. Several distinct sources of error are present, and these have each been discussed and estimates of their magnitude made from laboratory tests. In general, all errors increase rapidly above about 50 km. Certain items which had not been fully considered in previous discussions of this problem hale been shown to be highly significant. In particular it is found that the lead wires play an important part in determining thermistor response, particularly at high altitude, and that the temperature rise of the thermistor due to solar radiation is strongly dependent on the radiation absorbed by the lead wires as well as by the bead proper.