Vane anemometer having a modular impeller assembly

Abstract

A vane anemometer is disclosed in which a modular vane assembly is removably mounted within the case of the instrument. Within the modular vane assembly is a rotatably mounted impeller shaft. The impeller assembly preferably can be removed and inserted into a cavity of the anemometer without the use of tools. Consequently, if the impeller, bearings or other components of the impeller assembly should become damaged, the modular impeller assembly can be quickly and easily replaced. The modular impeller assembly is preferably mechanically insulated from the anemometer casing. This minimizes the effect of dynamic forces on the bearings and other components of the impeller assembly. A method of and the structure for precisely and reproducibly adjusting the axial clearance between a shaft and a bearing assembly is also disclosed. The vane anemometer of this invention may also measure the temperature and the wind chill of the ambient air. In order to accurately and quickly measure these parameters the vane anemometer may have a temperature probe that is disposed external to the casing of the anemometer. Preferably, the casing has an opening defined by a plurality of walls of the casing in which the temperature probe is disposed. The temperature probe may be coupled to a microprocessor by an electrical connector that extends from the casing. In order to thermally isolate the probe from the casing, the connector may be wound about itself.