The Multichannel Constant Temperature Anemometer

Abstract

Multichannel measurements are needed in many applications in fluid dynamic research. The constant temperature anemometer (CTA) is often the obvious choice of instrument , when especially time series are of interest, as it provides a continuos signal of high temporal resolution. Basically multichannel measurements are employed, when information about two or more parameters are needed simultaneously in order to describe the flow. Each parameter is represented by a continuos signal from a separate sensor operated from its own CTA-channel. The operation of multichannel anemometers have traditionally been considered a time consuming task, as it includes optimization and setup of a large number of parameters including both velocity and directional calibrations. In recent years computer controlled anemometers have become available that allows automatic setup and calibration of multiple sensor probes. Multichannel CTA measurements have thus become considerably more efficient and reliable.