An electronic-hardware-based oscillogenic controller previously developed by P. K. Mercure was used as a model for translation into a software-based control algoritnm. The oscillogenic instrument, invented by P. R. Rony and P. K. Mercure, uses a feedback element (the oscillogenic controller) and a sensor component to produces a periodic signal yielding information about the instrument's sensor component. A control program that utilized the oscillogenic control algorithm was written in the Turbo Pascal programming language. An IBM PC with 640 kilobytes of read/write memory and with analog-to-digital and digital-to-analog converter boards running the control program performed as the controller component of an oscillogenic instrument. A sample time of 0.5 seconds was used for this study. The instrument's sensor component consisted of a forced air thermal system with air flow rates ranging from 8.4 to 3l kg/hr. The oscillogenic instrument's frequency was, over the limited range tested (0.032 to 0.062 hz), a linear indication of the thermal system's convective heat transfer coefficient, which varied from 230 to 400 W/m²-°C. / Master of Science