The development of instrumentation for the support of skin friction and heat flux measurements
Instrumentation has been designed to process the signals from two types of skin friction gages and a microfabricated heat flux gage. Design changes for the skin friction gages are presented which will improve the performance of the two transducers. The instrumentation is simple in design and use and has been designed to maximize the performance of the skin friction and heat flux gages. The instrumentation is battery powered to minimize noise levels and to maintain instrumentation portability. A high-quality instrumentation amplifier, a voltage regulator, and a custom-designed circuit board have been combined to produce an instrumentation package which is stable and durable. The instrumentation has been specifically designed to handle low-level signals and can operate over a wide range of frequencies. Problems commonly associated with low-level signal conditioning like electrical noise, nonlinearities, and output drift are addressed. The performance specifications of the instrumentation are presented along with sample gage measurements.