A Digital Low Frequency Spectrum Analyzer, Using a Programmable Pocket Calculator

摘要

A measuring instrument utilizing Texas Instruments calculators (SR 52 or SR 56) is described. An application as a digital noise measuring system is discussed in detail. The instrument makes use of an input-output processor for the SR 52/56, developed by Verkroost, for which the design and testing of print lay-outs are reported. Results concerning sine-wave and noisy input signals are presented. For this application, the system shows no significant differences in properties with respect to the analog filters normally used for audio frequencies. The frequency range is, however, restricted to about 0.1 Hz, upper limit.