||A sound velocity sensor in a field-swappable body. These sensors can be exchanged between different Xchange instrument types, with each sensor head containing its own embedded calibration, allowing quick, easy, and on-site replacement of the sensor without impacting field accuracy. The SV-Xchange sound velocity sensor has a depth rating of 6000 m, a resolution of 0.001 m/s, and a response time of 20 ms. There are three options available depending on the intended application (typical oceanographic conditions, brine solutions, and special fluids). The instruments have ranges of 1375-1625, 1100-2000, and 500-2000 m/s, and accuracies of 0.025, 0.5 and 1.0 m/s respectively among the three application options.