Correlation between measurement of an ice detector and the mass of ice accreted on two different sized conductors

Abstract

In cold regions, atmospheric icing is an important parameter for the design and reliability of exposed structures. A test site, located on Mt. Valin (Québec) Canada, is used to obtain field data on icing events. This test site mainly includes two test lines supporting four types of electrical conductors, instrumentation, and an ice detector. The ice detector monitors ice accretion by measuring the shift in frequency, at resonance, of a vibrating cylindrical probe, under the effect of the mass of ice accreted. This instrument, which is electrically de-iced, sends a cumulative alarm signal for each ice mass accretion reaching a preset value. The correlation between the ice detector signal and the mass of ice accreted on two different sized conductors is presented for three typical icing events monitored during the 1994-1995 season. In order to improve the correlation, a procedure rejects the data points corresponding to the shedding of ice during an icing event. The comparison between the mass of ice accreted on different conductors and the ice detector signal is a convenient way to calibrate the instrument. Then, these results could be used for predicting the ice mass accreted on similar cables, using the number of alarm signals from the ice detector. Results indicate the need to take into consideration the cable diameter and the apparent area of the probe with respect to the direction of droplets in the calibration of such ice detector.Key words: ice accretion, ice detector, electrical conductor, correlation, calibration, icing model, ice prediction, in-cloud icing, precipitation icing.