There comes a time when virtually every engineer would like to simultaneously "log" how several parameters change over time. The results could simply be voltage from solar cells, or a voltage from a transducers measuring temperature, pressure, and other slowly varying physical phenomenon. The important thing is the sampling rate is not high but the duration of the measurement could be long. This application uses an HP 59313a four channel GPIB controlled ADC to create a 4 channel Data Logger with Engineering Unit support. Although the 59313a is "only" an 11 bit (10 + sign) bit ADC, this is quite adequate for many real world tasks.