Hewlett-Packard 299A DC Amplifier Chart Recorder

The Hewlett-Packard 299A DC Amplifier Chart Recorder is an instrument that combines a DC amplifier stage with a chart recorder to log DC voltage signals over time. It is powered by 120 VAC, and the designation 299A AB is noted in the product description. The unit accepts low-level DC inputs, amplifies the signal, and prints a trace on chart paper, providing a visual record of voltage changes as time progresses. This configuration supports applications in data logging, monitoring slow-changing DC signals, calibration tasks, and educational demonstrations where a persistent graphical record is valuable. As a Hewlett-Packard product, the 299A represents HP’s approach to integrating amplification and recording in a single instrument, simplifying measurement chains that require both signal boosting and a physical trace of the signal.