Mathematical Definitions for Transducer Measure Criteria

Effective instrumentation requires the solution of many problems. This is usually hampered by a lack of clearly defined criteria and the difficulty is compounded by the semantic uncertainty of the generally used descriptive terminology. This paper suggests some logical definitions, and their mathematical equivalents, for the most common transduction qualities so as to allow the formation of applicable sets of measure criteria. These are not only use ful for numeric compoutation but also provide a means for the comparative evaluation of actual or proposed systems. Some basic properties of all transducers are considered with respect to the statistical aspects of input-output relations. With these presumed or measured, and the purpose of transduction specified, it should be possible to determine a mutually compatible set of criteria. It may include such measures as accuracy, reliability, tolerance, precision, readability, sensitivity, and others. The development of an appropriate weighting function for the specified set of applicable criteria can be used to form a meaningful figure of merit which will provide a single dimensional measure for the value of the transducer in relation to the function it is intended to perform.