subject: Find Watch Glass Missing After Taking a Plane? [print this page] Recently ,a friend of mine told me that he found the glass of his watch gone after taking a plane,and the watch is an expensive one. This case may be an individual one, because the vast majority of people probably have not suffered from this before, even heard of such thing.But it is indeed likely to happen. Here ,we have to mention the atmospheric pressure?As we all know the altitude and atmospheric pressure are related, then the higher altitudes, the lower the atmospheric pressure ,which means that the atmospheric pressure willlessen when the altitudes increase. To a certain extent, the atmospheric pressure will decrease by1mmHg when the altitudes increase by12m.Now the aircraft flight altitude is about 10,000 meters. However ,in order to provide passengers with a safe and comfort flight, pressure must be added into the cabin.Even if so ,when aircrafts take off or land ,passengers will still suffer from ear pain, ear plug, eye pain and headache . That is because the pressureinside the body differs from the pressure outside the body.And eardrums and eyeballs are very sensitive .This just happened to me . Itwas difficult for me to chew and open mouth,and itwas only easy to yawn.Qualified waterproof watch must be a good seal one.There are two situation when the watch resists the pressure from the outside world :compression and decompression.In the compression situationthe watch glass and the table will be pushed harder and harder while experiencing compression ,it is just like vacuum pumping negative pressure,the watch glass and table will be affected by the force of outward expansion. Asa matter of fact ,watch need to have a waterproof test .At the same ,there is a way for the watch fo experience the negative pressure.That is like this:place it in a sealed tank ,then reduce the pressure to 400mmHg.Air space watch including watches intended for climbing mountains,all need to have this experiment specifically. As we can imagine?if the watch fails in the experiment,its glass will storm out . The pressure tank use in the experiment is equivalent of pressure cabin,the aircraft pressure cabin is just this like. Therefore, a flight for you means a test for your watch to some extent. If civil aircraft decompress suddenly at the high altitude, people would faint immediately.This will put passengers life in danger.A sudden decompression after compression will make the glass of bad -seal watch gone (except the completely waterproof ones). The in-depth diving watches also face such test. However,this won't happen tobad waterproof watches, because there will be a small gaps in the bad seal watch, which makes the pressure the same inside and outside the watch. As you can imagine now, the pressure differencebetweenthe cabin and the watch makes the glass fly out. In addition, if the glass do not combined with the case very well ,such problemcan happen more easier. Be careful ,if your watch has nylon seal between the glass and the case.Apparetly, watch glass is very thin.And the thinner the watch ,the worse the combination it has between the glass and case,then higher possibility of the lost of glass. My advice goes as follow:do not wear a watch in a plane,wrap it well into a bag.The best and most reliable way is to pull out the head table .I knowyour watch will stop going ,but it is reasonable .And you can install it back when finding nothing wrong with your watch after going off the plane.If the glass unfortunately drop out ,you can also find it in the bag easy and reinstall it . We should know the dial and the hands can be damaged easily without the potection of the glass .So it is important to find the glass timely if missing .
