Abstract: Apparatus for processing a sound transducer output by RMS and log converters over a wide dynamic range through automatic ranging circuitry sensing of log converter output to initiate range changes and fast averaging cicuitry responsive to range changes to implement the minimum RMS averaging time and to reset hold circuitry.

Abstract: An apparatus and method is described for automatically measuring the rate of decay of oscillation in mechanical structures, acoustical enclosures, and electrical circuits which have been suitably excited. The apparatus includes a source of excitation energy being applied by a transducer to one point to produce oscillation in the form of vibrations, sound, or electrical pulsations. To initiate measurement, the excitation is terminated, a dual trace oscilloscope is triggered, a data processing circuit is operationalized, and a reference decay rate signal is generated. A pickup transducer at a second point converts the decaying oscillation into an input signal which the data processing circuit absolute-values and log-converts to provide a decaying data signal for display as a slope on the oscilloscope. The reference decay rate signal is generated from an adjustable reference signal by integration and is displayed as a slope on the oscilloscope.