Swimming with Electronics - How to validate functionality?

My very first attempt to Dual Deployment was..... Ummm... ??? Interesting ???

Well the flight took a bit of a weathercock turn into the sun, so I didn't see anything until after the Main was deployed.

According to those that weren't looking directly into the SUN, the Dual Deployment went well.... Except.....

The whole thing landed in water...

The rocket is a Wildman Jr, so it survived the swim, but will the electronics?

After retrieving the water logged rocket, my son informed me that the Altimeter (Perfectflite Stratologger) was still beeping. I immediately turned off the power switch, and it is drying the rest of the way out.

My question is, "Will the self test be sufficient to validate that the altimeter is still fully functional?"

You should build yourself a pressure chamber like the one I use to test my altimeters
https://rocket.payload.free.fr/index.php?option=com_content&view=article&id=8&Itemid=6&lang=en

Adept also makes a little chamber from a plastic bottle that looks really easy to reproduce:
adeptrocketry.com/VCK2-VACBOTds.htm

The first thing to do is: remove power from it then, dry thoroughly!
Apply power then test.

JD

You might also want to put your altimeter in a WARM toaster over (about 150F) for a few hours, to help drive out any moisture from the baro sensor. These things don't like too much moisture... they ship with a dessicant in the foil pouch.

The best thing is to contact the manufacturer and see what his recommendations are.

Here is a build thread on an altitude simulator I built our of PVC for my MAWD tests:

https://www.rocketryforum.com/showthread.php?67170-Barometric-Flight-Simulator-for-the-MAWD

Greg

after racing fast electric race boats and seeing folks rescue their speed controls...first step disconnect the power(your switch is probably toast), second step, remove the water(ideally one would rinse with alcohol, but I've seen folk use 'WD-40'), next dry thoroughly(dashboard of a car works). after you get home pack in dry rice in an airtight container for several days, then test it out. those are basically the same steps I used after mine got dunked. of course if you really want to ensure that it works...order a replacement . good luck.
Rex

JohnCoker said:

Adept also makes a little chamber from a plastic bottle that looks really easy to reproduce:
adeptrocketry.com/VCK2-VACBOTds.htm

Click to expand...

Thanks. That little baby ought to do the trick....

I opened up the AvBay, and set it in the sun for the afternoon. When it was initially opened, the sled showed evidence that water made its way in. It also showed that most of the water was not in the area of the altimeter (although I could clearly see water droplets on the altimeter).

I got brave enough to turn it back on tonight, after it had dried. The flight data was present, and the self check ran and passed.

Sticking this questionable altimeter in a vacuum chamber, along with a control unit would give me confidence that the unit will work in a flight application.

I thank you all for your help!




Willie

If you don't have a test chamber, I would contact Jack and ask if he can bring his to the next meeting. He has one with LEDs to connect to the outputs so you don't even need an igniter.


Kirk

Rex R has it: Seal it up with dry rice for a few days. This treatment has revived an Ipod, a windows phone, and an RC boat receiver at my house.

After a couple days drying in a bag of rice, I decided to check out the functionality of the altimeter.

After removed from AvBay, wired up some Christmas tree lights, and a battery.


Shoved the whole thing in a very crude vacuum chamber. I used the shop vac in the garage to pull the vacuum.


Here is the resulting trace from shop vac. Not too bad... And, both lights fired as expected.


I reassembled the AvBay, and retested with my trusty Christmas tree lights.


I think am good to go for another dual deploy...


Willie