The Design and Development of a Particulate In-Situ Sampler (PARISS)

The accurate determination of concentrations of particulate matter in the deep ocean is complicated by the fact that such concentrations are extremely low. Consequently, considerable quantities of water must be filtered to obtain significant results. This paper describes a device which is designed to operate on a standard CTD cable to obtain insitu samples of particulate matter by filtering large measured quantities of sea water at moderate flow rates. The unit includes six banks of filters which can be sequentially engaged on command from the surface. This allows multiple samples to be collected from a single depth, or sampling at multiple depths from a single cast. The sampler is remotely powered and controlled from the surface, with information being transferred to and from the instrumentation package and the ship via a single wire. Test results indicate correct electro-mechanical operation to 2000 m however, some discrepancy with concentrations measured by conventional systems is noted.