Waterproof Quickcheck

Test if your device is sealed. The app uses the internal pressure sensor to detect specific pressure fluctuations while the user touches the screen.

A "Detailed" mode shows you a graph of the pressure development within the phone. If you open one of the phone's covers, you will recognize that the pressure does not change when touching the phone. Contrary, if the phone is sealed, there will be detectable fluctuations when the phone is touched.

Note: This app has been developed and tested for:
Sony Xperia Z3, Xperia Z3 compact

It may also work with other water resistant phones, like the Samsung Galaxy S5, but I need test feedback first.

WARNING: This app does NOT directly detect if your phone is waterproof. However, it gives you a hint of all covers and plastic flaps are closed.

WARNING: Whatever the app may show, under no circumstances apply excessive pressure or forces to your phone.

WARNING: If you just closed your phone's flaps and get a positive test result, you should wait a couple of minutes and repeat the test. Some users reported that their flaps pop slightly open after a while.

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FAQ:

There are other apps or manual ways to detect the sealing of the phone. What is special about this app?
This app analyzes the pressure within the phone AFTER touching it. It looks for a characteristic fluctuation of the pressure, while the built-in vent of the phone slowly reestablishes ambient conditions. In my opinion, this is more accurate that just detecting a pressure peak when touching the phone.

What is happening inside the phone? Where can I find more information?
I am no expert for this. I assume, the phone has built in pressure vents like e.g. http://www.gore.com/en_xx/products/venting/portable/cell-phone.html

When I try this with my phone (other that Xperia Z3), I get a "Not OK" Message and only one or zero stars. Does this really mean, that my device is not sealed?
Probably not. This app may need a specific adjustment for your device. Go to the "Detailed View" via the menu in the top right corner. Only if you see no clear pressure fluctuations at all, there is definitely something wrong with the phone.

What app permissions are needed?
None.

What data are transmitted over the network?
None.

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This App is open source and published under Apache license 2.0. Source code is available on GitHub.com.

CREDITS: Thanks to users alik (android-hilfe.de) , adamk7 and Bäcker (xda-developers.com) for sharing the idea behind this test.