Abstract: An apparatus for measuring dew-point of a gas stream includes a sensor cell having a probe, means for cooling the probe, means for transmitting light to the probe surface in a pressurized chamber, means for receiving returned light scattered from the cooled probe surface, and means for determining dew-point from a reduction in scattered light intensity. The probe surface is provided in its center with a depression of low angle.

Abstract: Method and apparatus for surveying positions of mooring lines extending between a moored structure and anchors in the water bottom comprising a rotatable submarine transducer assembly including acoustic pulse transmitting means and an array of acoustic receivers, a support for locating the transducer assembly at a predetermined level above the water bottom and actuator means for rotating the assembly about a vertical axis relative to the support. During operation the transmitting means produces a beam of acoustic pulses. Pulse reflections originating from mooring line sections that are successively scanned by the beam are received by the acoustic receivers, and the position of each scanned mooring line section is calculated by a processor unit on the basis of the time interval at which the pulses are received after transmission.