An Electronic Zooplankton Counting and Sizing System

An automated zooplankton sampler has been developed which counts and size-classifies particles in the 0.3-3mm diameter size range. The system uses a multiple-orifice sensor developed by C.M. Boyd [1]; subsequent elements of the system (electronics hardware, built-in microprocessor, and Hewlett-Packard 85 desktop computer) have been redesigned to allow programmable size classification (ten size categories), automatic tests for bad data (due e.g. to sensor blockage or electronic failure), and logging of up to eight external data inputs.