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 cage. Some simple changes to the VMCM's A/D (analog/digital) 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 and the A/D sampling cycle. Some sensors with low power consumption were powered continuously and their signals passed through a low-pass filter to match time constants and minimize aliasing. Sixteeen VMCM's were modified and three deployments of these MVMSs (multivariable moored sensor) were made in 1987 with durations of 3 to 4 months as part of Biowatt (Bioluminescence and Optical Variability in Sea) II. Data return was better than 80%. Reasons for loss of data include tape breakage, underwater connector failure, pressure case flooding, and fouling.
|Title of host publication||Unknown Host Publication Title|
|Place of Publication||Piscataway, NJ, United States|
|Publisher||Publ by IEEE|
|Number of pages||7|
|State||Published - Dec 1 1988|
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