Combo Probe System

Combo (Hot-Film/Sonic-Anemometer) Probe System

The ‘combo probe’ was in-house designed, and consists of a sonic anemometer and constant-temperature hot-film probes arranged in a three-dimensional (double-X) sensing probe configuration. The hot films are located within the probe volume of the sonic anemometer. The hot-film probe of the combo was pivoted on a precision-motorized gimbal that could rotate to align the probe tip with the direction of oncoming winds detected by the sonic anemometer. Approximate alignment of the probe with the mean winds is a requirement for accurate hot-film measurements. The sonic anemometer measures the three components of mean winds and turbulence (resolution ~ 10 cm), and these measurements are used to calibrate the hot film (resolution ~ 1 mm) that could measure down to Kolmogorov scales.