L.A. Dedini K.J. Leap 1982 The design of a microprocessor-based data logger, which collects and digitizes analog voltage signals from a continuous-measuring instrumentation system and transmits serial data to a magnetic tape recorder, is discussed. The data logger was assembled from commercially-available components and can be user-programmed for greater flexibility. A description of the data logger hardware and software designs, general operating instructions, the microprocessor program listing, and electrical schematic diagrams are presented. application/pdf 10.3133/ofr82167 en U.S. Geological Survey, The design of a microprocessor-based data logger reports