Multiplexer displays two pressure signals on single oscilloscope channel

High-fidelity pressure transducers may drift during long experiments. To correct for this drift, many investigators periodically rebalance the high-fidelity transducer, comparing the results from the high-fidelity transducer with those from a fluid-filled catheter connected to an external transducer. This procedure is subject to error because the high-fidelity and reference signals have to be displayed on different oscilloscope channels; thus these channels can drift differently, being subject to parallax and other problems. This procedure also requires two display channels, which are often in short supply during two display channels, which are often in short supply during complex experiments. We present a design for a multiplexer that will display two pressure signals on one oscilloscope channel, thereby solving these problems and saving one channel to display other information.