Leak Sentinel from Vivid Housings

[divengolf 17]

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

[E_viking 30]

You will be happy with it. It works nicely.

[Johnqdiver 3]

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.

[tdtaylor 1]

 

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

[Interceptor121 702]

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/

[adamhanlon 0]

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

[Interceptor121 702]

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

[adamhanlon 0]

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

[oskar 6]

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

[Interceptor121 702]

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

[oskar 6]

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

[Interceptor121 702]

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

[adamhanlon 0]

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

[Interceptor121 702]

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

[Stuart Keasley 42]

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.

Edited March 21, 2014 by bottlefish

[Stuart Keasley 42]

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

 

Probably not... The air inside will start off hot, then cool down win you hit the water, the air inside will contract with the temperature change reducing the pressure differential even further, ie it would be pushed further away from the trigger point.

[Interceptor121 702]

False positives only arise when the air temperature in the housing increases. This can be due to change of conditions i.e prepare the housing in an environment significantly colder than the water you dive in, but most importantly by the camera inside heating up as it is used

Especially for video you can easily reach 35C when you shoot a lot, if you prepared the housing in a dry air conditioned room that makes a 15C differential that is almost guaranteed to give false positives if you just did the additional stroke

You can create more vacuum to make the system more resilient I have suggested an update to the documentation the formula is rather simply see how many strokes you need to get to green and then multiply this for 0.2 and round up.

Another 40 mbar vacuum create no issue and don't make the device less reliable. Beside I have been told the temperature sensor is already there is the software that does not account for it

[mcliffy2 10]

Just thought I'd chime in with my experience using this in the Galapagos for a 7 day live aboard and 2 days of land based diving. It worked perfectly. Great peace of mind in my opinion. We dove waters that were a bit colder (65F), when it was 90F outside, with no issue.

[Stuart Keasley 42]

You can create more vacuum to make the system more resilient I have suggested an update to the documentation the formula is rather simply see how many strokes you need to get to green and then multiply this for 0.2 and round up.

 

That'd help to stop false negatives but could also stop notification in a true positive, I.e when pressure was increasing due to a breach in the housing not an increase in temperature.

[Interceptor121 702]

You are talking about a delta of 30mbar so not a great deal of difference. I think getting false positives is more annoying as you may disregard a real positive. Miso agreed to change the documentation and put this suggestion in case you prepare the housing in environment colder than the water you dive

[E_viking 30]

Hi,

 

I have used it quite a bit over the last year.

 

The only false alarms I have gotten was while rinsing it in the Bathtub after diving.

When I by mistake have tapped up to warm water :-)

 

Apart from that it is working nicely.

 

/Erik

[JDelage 0]

All,

 

I just bought one of those (Leak Sentinel V3). It came today, unfortunately without a user's manual. I have sent Miso an email. In the meantime, I have a couple questions:

 

1) How do you place the battery? On post #12, PeteAtkinson shows a picture on which the battery sits below the circuit board? If that's the case, how do you remove the board?

2) Is there a way to turn the unit on/off, or do you do that by removing the battery?

3) Do you travel with the unit on the housing?

 

Thanks,

 

Joss

 

EDIT: Miso had emailed me the user's manual in a separate email before the unit arrived. It's my mistake I missed it.

Edited April 10, 2014 by JDelage

[Interceptor121 702]

It comes with a battery installed already. The unit turns on and off. You definitely need the instruction I will send them to you

[JDelage 0]

I'm still curious as to whether people travel with the unit attached or set it up when they arrive on location.

[Interceptor121 702]

I take it separately and set up at location.