CHARACTERIZATION OF NEW TEMPERATURE SENSOR BASED ON QUARTZ TUNING FORK OSCILLATOR

S. Lorefice, E. Pessana, R. Romeo
Abstract:
A new temperature system based on low cost quartz tuning forks, originally designed to be used in wristwatches, has been arranged for temperature measurements in a wide cryogenic temperature range from 77 K to 273 K.
The present paper concerns small quartz crystal tuning forks, with a fundamental frequency of 32768 Hz, as a temperature sensor by measuring the resonance frequency shift caused by an external temperature. Special attention has been given to the methodology, equipment and design to improve the stability in time of the output signal of the quartz tuning fork temperature sensor. After temperature calibration, a statistical study has been performed to estimate the parameters/coefficients of the fitted curves by using a Weight Total Least Squares “WTLS” method. The chi-square test has also been considered as an indicator of the agreement between the observed data and the predicted values.
Higher-order polynomial curves seem to be the ”best fits” for the experimental data provided by the temperature system. The study also shows a significant statistical improvement by introducing the fractional degree of 0.5 in the regression curves, in particular for the third degree polynomial regression. Moreover, the fractional polynomial curve results in a better smoothing of the experimental irregularities encountered at low temperatures.
Keywords:
thermometer, quartz tuning fork, temperature measurement
Download:
IMEKO-WC-2015-TC12-256.pdf
DOI:
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Event details
Event name:
XXI IMEKO World Congress
Title:

Measurement in Research and Industry

Place:
Prague, CZECH REPUBLIC
Time:
30 August 2015 - 04 September 2015
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