Description of conversion of an EGG VMCM into a MVMS(multi-variable moored sensor)

摘要

A standard EG&G VMCM (vector measuring current meter) has beenmodified to acquire data from external sensors. The external sensors aremounted on a compact backpack which attaches to the VMCM's cage. Somesimple changes to the VMCM's A/D (analog/digital) board opened up eightanalog voltage channels. Changes to the VMCM's firmware were made toallow control over the period of time between toggling external power onand the A/D sampling cycle. Some sensors with low power consumption werepowered continuously and their signals passed through a low-pass filterto match time constants and minimize aliasing. Sixteen VMCMs weremodified and three deployments of these MVMSs (multivariable mooredsensors) were made in 1987 with durations of three to four months