This is a good way to see if your phone can survive a dunk in the pool.
Today I learned that you can test the water resistance of a smartphone without throwing it into a giant pool. All you need is a water resistance tester app, like the one that’s been making the rounds on Reddit.
The aptly named Water Resistance Tester app is available for Android devices in the Google Play Store. It tests your smartphone’s IP67 and IP68 water-resistance seals by way of the barometer built into your phone. Two Redditors in the Samsung community, where the post originated, confirmed and then deleted a note saying that the methodology is similar to how OEMs test the seal on their devices. We’ve reached out to Samsung to confirm whether that’s actually the case.
To start the test, place your phone on a solid, flat surface. Then, place your thumbs on the screen where indicated. Once you apply a bit of pressure, the test will start. The app will flash a green checkmark if everything seems as sealed as the day you took the phone out of the box. And if it’s not, you’ll have trouble starting the test, and then you’ll get a giant red exclamation mark to let you know your phone is not resistant to water. Android Police also notes that if you run the test with a popped-out SIM tray, the test will fail since there’s a giant gaping hole where water could theoretically seep in.
The barometer inside a smartphone measures relative air pressure around the device. Back when smartphones were just getting gussied up with premium features, the idea of a barometer inside such a small device seemed like a far-off ideal. Barometers are typically water-based or use a copper alloy solution that expands and contracts based on atmospheric pressure. But that’s too mechanical for a smartphone. Instead, a digital barometer is used to do this testing. It’s a simple pressure-sensing transducer, often found in the dedicated GPS chip. It measures pressure in Pascals, which is what “hPa” stands for on the results of the Water Resistance Tester. Phone barometers are so powerful, you could even DIY your own scale if you wanted.