Grounding Issues

We are mounting a Vectrino in a laboratory flume and initially noticed a lot of background noise in the Probe Check and other signals.  The noise reduces when we unplug nearby motors and route the Vectrino cable away from other electrical devices.  Have others had grounding issues before, and if so, how was the issue solved?  We believe the noise is radio frequency interference.

If we attached a grounding wire to the stem of the ADV and place the other end of the grounding wire in the water, the noise reduces quite a bit.  Even still every few seconds a periodic signal shows up while doing a Probe Check.

How is the Vectrino set up to run off a battery, and how can we log the data internally?  What is the limit for storage space when logging data internally?

Any help is appreciated, or any stories about similar situations happening.

Thanks!

Dear Craig

Noise from motors is not uncommon in laboratories. Your solution makes sense - grounding the probe and/or the water isa good way to go,

The Vectrino is not designed for operation with internal battery/data logger.  The "Vector" is the larger field instrument that collects velocity data much the same way as the Vectrino and has interal orientation sensors, batteries, and recorder.

Best regards, Atle Lohrmann

Thanks for your response, Atle.  Are there any better methods to reduce electrical noise other than using a grounding wire placed in the water and turning off nearby motors?  Anything within the Vectrino software that would optimize the quality of signal response? 

-Craig

Dear Craig, the only other thing I can think of is to coil up any excess cable from the computer to the Vectrino. 

- Atle