Ocean Monitor CTD-1. The CDT-1 is a minature direct reading salinometer for the gathering of accurate salinity, temperature and depth data. It acquires precise conductivity, temperature and pressure data from high stability sensors. Salinity, density, depth and sound velocity are then calculated. The titanium pressure housing of the CTD-1 ensures maximum resistance to corrosion. The pressure housing is 88mm diameter and 374mm length. The rear-end cap is fitted with the pressure and temperatureand conductivity sensors and two wet pluggable underwater sensors. Each end-cap is secured by an internally screw-threaded locking ring.