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Can the pressure sensor fail in a way that would cause a leak


(Robert) #1

I was recently performing a series of dives with my BlueROV2 to depths from 200 to 310 feet. After a few dives I started getting errors associated with the pressure sensor. It’s been over a month now so I don’t recall the exact error. Associated with the error the depth readings became erratic. Depth was all over the place.

The bigger issue is that after a couple more dives the ROV started leaking. I’m wondering if the pressure sensor can be the source of the leak?

Things I did relative to leak testing and repair:

  1. ROV holds 18" of Hg no problem for over an hour.
  2. Noted that it appeared water was getting past potting or coming through jacket of the power lead from the battery. I needed a field fix to keep the project alive so I used heat shrink around the outside of the fitting, filled with 3M 5200, shrank a little more, put in hotel bathroom with shower running because 5200 sets up fast in humid environment.
  3. Still leaked so changed out the front camera dome for fear the bonding to the flange had failed.
  4. Changed o-ring for the penetrator associated with the power lead
  5. Changed the large housing O-rings for the end caps.

At the end of the day I had to give up and not get all the data required by my client. After various dives with leaks I had burned one thruster board and camera. I had spares for those but all my leak detectors had become compromised by being shorted due to leaks. At the end of the day I’m guessing it’s the penetrator for the power line and the 5200 just didn’t solve the problem or it’s the pressure sensor.

Any ideas to better pressure test without doing dives or ideas on the pressure sensor appreciated.


(Adam) #2

Hi Robert,

I would be very surprised if the pressure sensor were the cause of the leak- there are a lot of Bar30s out in the world, and we’ve never seen one or had anyone else have one leak. It is possible, but very unlikely.

The power cables however can be sensitive during potting, and I strongly suspect your leak can be tracked down to there. You can contact us at support@bluerobotics.com, and we’ll get a replacement to you as well as troubleshoot the pressure sensor if you’re still having problems with it.

To track down a particularity pesky leak, it is possible to do a lot more aggressive vacuum test, leaving the test running overnight or even longer. Air can leak through the other end of the tether, so this needs to be removed and plugged with a rubber stopper. Any vacuum pump will also leak slowly, so a ball valve before the ROV is also needed.

-Adam


(Robert) #3

Hi Adam,
Thanks, I will reach out through support. I have some other items I need so maybe we can setup an order and ship all at once. I do have a bulkhead fitting and matching termination on my tether. Probably why my ROV holds vacuum so well.

I agree the power cable is most likely culprit. Just couldn’t believe my slathering it with 5200 and heat shrinking didn’t at least temporarily stop the leak.

Cheers