fun to play with.

Just testing out my new leak tester.

The watch is placed on a platform under a dial indicator and the probe is placed on the crystal and the dial gauge set to zero. The cover is put on and the vacuum pump is run for about a minute. If the watch leaks like a sieve, the needle will not move.

If the watch is airtight, the atmospheric pressure inside the case will expand the case and move the needle on the dial. It's all allowed to sit for about five minutes and if the reading is still unchanged, the watch case can be considered airtight, and therefore, reasonably water resistant.

If it needs further confirmation, a water dunk tester can be used, but this is a good check for normal "water resistant" watches.