Plankton Counter

The Laser Optical Plankton Counter (LOPC) is the next generation in plankton profiling. The LOPC's high speed processing and improved detection plane provides detection counts at higher resolutions and higher concentrations with lower coincidence.

This also allows the LOPC to be integrated into tow bodies such as the Moving Vessel Profiler (MVPT), traveling at up to 12 knots and still providing reliable data. However, the LOPC is designed to be adaptable to any tow body and operate stand-alone as well.

The image to the right is a LOPC Software screen capture showing data collection during a calibration check. This data is produced by dropping various sized micro-beads (extremely small, precision-machined glass beads, often resembling powder) through the tunnel of the LOPC. The histogram in the main window displays the counts vs. size distribution (number of beads detected) for the smaller beads, while larger beads (>1.5mm) are displayed in the scrolling window to the right of the histogram. Sufficient data can be collected from larger particles to reproduce a shape outline or profile and these are displayed in real-time as they pass through the tunnel.

When external sensors are attached, such as an Applied Microsystems Limited (AML) CTD, the data is integrated into the LOPC data stream and displayed in various text boxes (the control bar across the bottom of the screen), as well as, in time-based strip-charts as those in the screen shot to the left. This particular data set was collected with an LOPC and an AML CTD integrated in a Moving Vessel Profiler (MVP). The time-based plots in this screen shot show Depth, Salinity and Counts Per Second (CPS). Other available plots are Temperature, Counts Per Second (Windowed), Counts Per Volume and Flow Speed. Any combination of these plots can be selected while underway.