Leak Sentinel from Vivid Housings

Leecat is correct - I tried that with a view to saving battery consumption and got the red LED the following morning which worried me a bit. When I equalised the pressure and evacuated the housing again, all was well. Didn't understand why but Leecat's explanation has removed a minor niggle at the back of my mind.

I confirm Okuma's experience of this unit - just dived two weeks in Scotland using the Leal Sentinel on an Aquatica housing and it worked flawlessly.

to okuma and JimG: I'm very happy I could help you. One more suggestion: RTFM, sometimes it helps

If anybody prefers electric pump, this one works well with leak Sentinel:

http://www.ebay.com/itm/Handheld-Food-Saver-Fresh-Saver-Vacuum-Sealer-System-with-2-Bags-/321177546499?pt=LH_DefaultDomain_0&hash=item4ac7ac6f03

It fits the pump cap without the tubing. So if the reason for leaving the housing under vacuum overnight is avoiding pumping, electric pump might be the solution, it evacuates the housing in seconds...

Any word on whether the Nauticam vacuum product is on the market yet?

Used my v3 Leak Sentinel in Bonaire for a week at the end of last month, and worked flawlessly. I did request a second cap, being that between this and the housing there are lots of small pieces to misplace. The second cap was sent immediately at a very reasonable price.

Also, I use one on a Nauticam OM-D housing, and it reduces to the proper pressure in three strokes. I always add one more just for caution's sake.

Recently I purchased a Leak Sentinel V3 from Miso. Delivery was prompt. I installed it into the microphone port of my Aquatica D7000 housing without problem. Removing the microphone was a bit of a trick as my fingers are not the smallest in the world, but eventually everything fit fine. The unit came with a spare battery in addition to the installed battery; a nice gesture. I ordered an additional cap as small parts tend to get lost.

I bench tested the unit and it performed as expected. It went to a blinking green light indicating proper vacuum after about nine cycles of the vacuum pump. I then did three more cycles of the pump and left it overnight. It held vacuum all night as evidenced by the blinking green light in the morning.

The unit is well engineered. Miso has been very responsible to my questions. At about € 200, this is a great insurance on your investment.

So far so good. I'll be diving the rig in a couple months and will post further comments then.

Harry

You will be happy with it. It works nicely.

I was waiting for the Nauticam unit to come out to retrofit it to my Nex-6 housing, but the housing is to small for the PCB etc, so I was recommended the Leak sentinel. After reading the Vivid website and this thread I placed an order.

Basically the same level of protection as the Nauticam without having to replace any parts as the housing still has it's built in water alarm.

Looking forward to the peace of mind it will hopefully provide.

Another 26 dives last week with the Leak Sentinel, and worked just as it should. So far, about a hundred dives using the unit. I did replace the battery as a precaution 26 dives ago, and took twice to reassemble properly. Had to make sure the circuit board was firmly seated between within the o-ring. After that, no problems.

Terry

I have done some bench tests and managed to get false positives shooting continuous video

I wrote Miso to change the instructions and advise users not to prepare the housing in an air conditioned room if you then go diving in very warm water

http://interceptor121.wordpress.com/2014/03/09/leak-sentinel-v3-for-rx100-mark-ii-review-and-stress-bench-test/

My experience of constant monitoring of internal pressure is that it tend to produce these "false positives."

If the assembled housing will hold a vacuum for 10 minutes or so pre-dive, then it is very unlikely to leak thereafter. Lights, circuits etc add a level of sophistication, expense and complexity that does nothing to actually validate whether the housing will keep water out or not once you are actually diving.

Not to mention that they produce an annoying bright light!

Adam

In general terms this is a good product to do a pre-dive check. I suggested some changes to the user documentation as in specific cases you can get false positive but those are pretty much identified and should be dealt with accordingly

I also have a moisture sensor as a second way of checking and I think the combination of the two is better than putting the camera in a bucket as a pre-dive check

You are right that you could test the vacuum and then switch off the monitoring afterwards and leave it to the moisture sensor to deal with

I believe that if your housing is water proof and then you hit it underwater and it cracks somewhere on a port or LCD screen the chances are you are not going to save the equipment anyway

Agreed, if you manage to break the housing somehow, no vacuum or any other system is going to help....

In the past, i actually missed out on commercial shots because the housing's vacuum system had flagged up a false positive. To me, whilst the value of my equipment is important, the actual shots it can produce are what actually matters. A system that effectively precludes my getting in the water because of a temperature change is more hinderance than help.

I have recently been in the water at night with people with continuous monitoring systems-man those lights are bright!

Adam

The Leak sentinel system is about half price compared to the cost to retrofit my Nauticam EM-5 housing with the proprietary vacuum systems.

What are pros and cons if you compare them?

Cheers

/O

The Leak sentinel system is about half price compared to the cost to retrofit my Nauticam EM-5 housing with the proprietary vacuum systems.

 

What are pros and cons if you compare them?

 

Cheers

/O

The Nauticam system has temperature compensation, currently the Leak Sentinel does not have this feature.

In my view if you follow the guidelines there is a low risk of having issues with false positives. If instead you are one of those guys that prepares the housing in a cold air conditioned room I would say currently nauticam is the only way to go

I'm one of those guys who prepare the husing in a heated room of 24 degrees C then jump into 3 degrees C water ;-)

sounds like a case for false negative perhaps

The Nauticam system has temperature compensation, currently the Leak Sentinel does not have this feature.

In my view if you follow the guidelines there is a low risk of having issues with false positives. If instead you are one of those guys that prepares the housing in a cold air conditioned room I would say currently nauticam is the only way to go

Lol no issue going colder it could indeed increase the vacuum and the time until a leak is detected but the cold water will also cool the housing and the camera down. Practically no risk

Actually, I have had numerous false positives going from warm to cold...

Based on my experience, I think (and may be wrong) that most of these devices use pressure change, rather that increase vs decrease as a trigger.

Temperature compensation is tricky. If the circuit allows a decreases in vacuum, this could be due to temperature change, or a leak!

Adam

The leak sentinel stores the initial ambient pressure and then blinks at -200 mbar from there. Once you exceed that value it will start blinking

With temperature compensation you can constantly change that alert value as temperature changes

Going from warm to cold generally helps however if the device inside the housing makes the air warmer than it was at the beginning than you have similar issue

Example you prepare the housing indoor at home say 20C, you then go diving in 10C water. The camera warms up and goes higher than 20C however the water cools down the housing and that in turn cools down the air. So you have a cooling effect and a warming effect. however if the camera does get really hot say 35C and the water does not manage to cool down the housing maybe because the housing is plastic you are back to the initial situation

in general it is very useful to have an integrity check pre-dive better than a rinse tank but the actual monitoring is only reliable with temperature compensation especially if the housing is quite large

We've fitted a leak sentinel to our FS700 Amphibico Genesis housing. On the whole it's worked flawlessly, however on a couple of occasions, moving from cold top side to heated pool and then filming 2k raw HFR for extended periods the red alarm light has started to flash... The heat of the air inside the housing has obviously raised enough to increase internal pressure above the trigger point.

I therefore view the leak sentinel as a valuable tool to check the integrity of the housing before a dive. If it holds negative pressure for a reasonable period before the dive then a leak during the dive would have to be caused by a physical failure.

So with that in mind, I wouldn't suggest anyone changes their predive camera set up routine to avoid a false reading during the dive. Kitting up in a dry air (e.g air con) room helps avoid condensation issues, being in a quiet room generally helps you focus on what you're doing and keeps you away from the elements and sea air.

Just accept the foibles, understand what the monitor is doing, if the false positives give you the heebie freebies, turn off the monitor after you've done your check.