Description of Conversion of an EG&G VMCM (Vector Measuring Current Meter) Into a MVMS (Multi-Variable Moored Sensor)

摘要

A standard EG&G VMCM (Vector Measuring Current Meter) has been modified to acquire data from external sensors. The external sensors are mounted on a compact backpack which attaches to the VMCM's Analog to Digital (A/D) board opened up eight analog voltage channels. Changes to the VMCM's firmware were made to allow control over the period of time between toggling external power on an the A/D sampling cycle. Some sensors with low power consumption were powered continuously and their signals passed through a low pass filter (TC 8 min) in order to match time constants and minimize aliasing. Sixteen VMCM's were made in 1987 with durations of 3 to 4 months apart Biowatt II. Data return was better than 80%. Reasons for loss of data include tape breakage, underwater connector failure, pressure case flooding, and fouling. Keywords: Biowatt (Bioluminescence and Optical Variability in the Sea); Oceanographic equipment; Optical detectors. Reprints.