Fine wire resistance thermometer amplifier for atmospheric measurements

Harrison, R. G. ORCID: https://orcid.org/0000-0003-0693-347X and Rogers, G. W. (2006) Fine wire resistance thermometer amplifier for atmospheric measurements. Review Of Scientific Instruments, 77 (11). p. 116112.

Abstract/Summary

An improved amplifier for atmospheric fine wire resistance thermometry is described. The amplifier uses a low excitation current (50 mu A). This is shown to ensure negligible self-heating of the low mass fine wire resistance sensor, compared with measured nocturnal surface air temperature fluctuations. The system provides sufficient amplification for a +/- 50 degrees C span using a +/- 5 V dynamic range analog-to-digital converter, with a noise level of less than 0.01 degrees C. A Kelvin four-wire connection cancels the effect of long lead resistances: a 50 m length of screened cable connecting the Reading design of fine wire thermometer to the amplifier produced no measurable temperature change at 12 bit resolution.