An agreement to jointly manufacture the world's first expendable ocean salinity, temperature, depth (XSTD) measuring system has been made by Plessey Environmental Systems and The Sippican Corporation of Marion, Massachusetts. According to news releases this Expendable XSTD System provides a simple and economical method for obtaining salinity and temperature data as a function of depth from the ocean environment. It is designed for operation to depths of 750 meters over temperature and salinity ranges of −2° to 35°C and 30 to 40 ppt. Applications of the XSTD include ASW, commercial, oceanographic, and fishing investigations.
It is reported that in operation the XSTD is quickly and easily launched from a moving ship and that the sensed data are transmitted through a fine wire from an expendable probe to data processing equipment on shipboard. The insulated conductor wire is dual-spooled, allowing independent dereeling that assures vertical descent of the probe after launch from the deck of a moving vessel.