Dedicated microprocessor system to control laser Doppler velocimetry measurements and to reduce data

Abstract

A dedicated microprocessor system has been developed exclusively to control and reduce data from a two-component laser Doppler velocimeter (LDV) which uses counter-type signal processors. The system control and data-acquisition/validation software residing in the EPROMs has made the LDV system a stand-alone instrument. The measurements are initiated through a hex keypad where each key is programmed for a specific function including traverse of the optics. During measurements, blocks of 16 kbytes of raw data are transferred to a mass storage for detailed postmeasurement analysis. The system is also provided with a general purpose interface bus (GPIB) to enable access to a centralized data-acquisition network. The overall LDV system is portable and has been successfully used in field measurements at various magnetohydrodynamic (MHD) facilities and in other laboratory applications.