Water won't enter inside the device!
IF YOU WANT, ALL IS IN THE PHOTO, (EASY & FUNNY INSTRUCTIONS)
Step 1: Materials and tools
A big plastic bottle (5 or 8 L or more depending of ur device size)
Water (better if it's distilled, to prevent incidents)
An air pump with the stem (to inflate balls)
A stick to put inside the bottle
The device/gadged to test
Gluegun and silicon/termoglue or adhesive tap.
Step 2: Preparing the test
The device must be able to enter inside the bottle through the bottle's top. If it can't, you'll have to do an alternative entrance for the device to test. (It have to be hermetic the alternative entrance).
Now you only have to do a small hole to insert the air pump. In the bottle's top, works good.
Step 3: Doing the test
( If you want, use distilled water, if the test has an incident, distilled water is less harmfull for your watch/device. But, it's improbable to have problems with the test. )
hang your watch/gadged from the stick inside the bottle. ( the device mustn't touch the water )
Close the top, or the alternative orifice hermeticaly.
Now insert the pump, and pump air inside the bottle.
Air pressure will increase.
When there are the wanted pressure, incline the bottle to drop the watch/device inside the water. The pump must be still connected to the bottle to keep for a seconds the air pressure.
Now with the divice inside the water, let the air scape from the bottle, the air pressure will drop.
If the watch or device weeps air bubbles, it isn't waterproof/WR.
If the watch or device don't weeps air bubbles, it's still WR!!
Step 4: The End!
If the watch/gadged it is not wr, it won't be hermetic to air too. So if when we have increase the pressure, inside it, the air pressure, have increassed,.
When we put inside the water with the high pressure, and we decrease the pressure, the air inside the watch wants to leave and exit the watch. So bubbles weep from it.
YOU CAN USE BOTTLES LIKE BOTTLES IN PHOTOS, AND SIMPLE BICYLE PUMPS!
SEE THE PHOTO!, THAT'S ALL ON IT!