A New, Low-Power Consumption, One-Dimensional Sonic Anemometer-thermometer

Abstract

A low power (0.1W) and light weight (probe weight 270g and circuit weight 80g) one-dimensional sonic anemometer-thermometer was developed. The measuring span of the anemometer is 10cm, sound frequency is 40kHz and alternation frequency of the sound direction is 78Hz. The low power consumption was attained by using ceramic transducers, which can be driven by low voltage pulses (5V peak-to-peak) and by adapting CMOS logic to the circuit.
A field test was carried out in a coniferous forest with a commercial sonic anemometer and a fine thermocouple thermometer. Comparison of the output signal and spectra from each sonic anemometer indicated good agreement.
The characteristics of the sonic anemometer-thermometer are low power consumption and light weight. These features are useful for measurements from a small tethered balloon or at places where the electrical power is limited.