A chart recorder is an instrument used to record various process and electrical signals. The most traditional chart recorders record data on paper. The paper is passed under a pen and the pen i deflected in proportion to the signal. The result is a graph or chart of the data. Chart recorders are available in single or multichannel styles (single or multipen) and in various configurations. Many of today’s chart recorders can also record information in a digital format for download to a computer.