Water Resistant from a Wrist Watch
	General information Water and clock mechanics do not get along. Water in the mechanic is worse than the proverbial sand in the transmission - rust is the mortal enemy of fine mechanic, paralyzes impulses and brings each balance spring from these. It is nevertheless sometimes inevitably (rainstorms) or desired straight (waterproof watch) that the clock into more or little intensive contact with water comes. Each owner of clock should be exact - and exeptionally also the trailers of the quartz parliamentary group are here addressed - in the picture, which he can zumuten its clock in the wet element. By adequate handling the clock as well as by attention of some basic rules (> practical references) one to remain spared from unpleasant experiences. Pressure measurement For the measurement of the pressure under and over water the unit is bar used. The unit describes the pressure, which affects surface of a body 1 cm ². Ashore prevails on sea level a pressure of 1 bar - each square centimeter of our body is loaded with 1 kg. With the ascent on a mountain the air pressure decreases, when immersing in water increases it. Due to the larger specific density the increase of pressure is clearly steeper in water - per 10 m depth rises the pressure by 1 bar. Thus depth of water already prevails a pressure of 2 bar in 10 m! For the indication of tightness on clocks the unit became generally accepted “atmosphere” at. If one neglects roundness differences, then one can set at for 1 bar = 1. Accurately the conversion reads: 1 bar = 0.980665 at (atmosphere) Examination of the water resistant In order to examine, whether a clock is waterproof, the watch maker has different possibilities: 1. Wet test In a chamber, which is filled with water to the half, a positive pressure is produced. The clock is dipped from the air-filled half into the water, the pressure is slowly decreased. If the clock is leaky, by the positive pressure dominant in the clock air is outward pressed by the leaky place - at the leakage small air vesicles form. 2. Dry run In a chamber positive pressure is produced. A sensor (fine pointer), resting against the housing, measures thereby whether at the housing a size change results. This is only with close clocks the case, since from the positive pressure in the chamber in the clock a negative pressure results, which deforms glass and soil minimum. With leakage the pressure does not adapt itself it inside the clock, deforms. 3. Condensation test Somewhat adventurously the third test variant, the condensation test appears to me. The clock is put approx. a half hour into a container with water. Subsequently, the clock is warmed up and deterred with cold water. If water behind the glass condenses, the clock is not waterproof. Then the child is (controlled) in the wells however already pleases - the clock must be opened and dried. DIN 8310 The term “waterproof” (more water resistant) is specified in the DIN standard 8310. Afterwards a clock is considered as waterproof, if it exists when new the pressure-technical examination according to DIN 8310: 30 minutes of 1 m water gauge (~ approx. 1 bar) afterwards 90 seconds of 20 m water gauge (~ approx. 2 bar) With the test pressure 10 meters of water gauge correspond to approx. 1 bar, the clock in this test a maximum pressure by 3 bar are thus suspended. Importantly to know it is however that it concerns here an even static Kraft, which affects the clock case. When swimming in 20 meters depth additional components affect the clock, which increases the load clearly. One up to 3 bar waterproof clock can be thus never used for a dipping course up to 20 meters of depth! Note: The long time usual designation “more water proof” was replaced by “more water resistant”. Gradations Usually the permissible maximum pressure is registered on the clock. On the housing bottom the pressure is indicated in at, proven on the number sheet against it it in meters. The following table informs about it, a clock can be exposed to which loads. Here it does not concern standards, on the contrary are this general empirical values. Specification on housing bottom Designation Small contact with water (rain,  handwash) Contact with water (wash off, kitchen work, bathe) Water haven (swim, to snorkels, shower) Equipmentdip (with pressure bottle) Low-dip (with helium oxygen mixture) with out spezification not water resistant - - - - - 3 atm water resistant x - - - - 5 atm water resistant 50m x x - - - 10 atm water resistant 100m x x x - - 20 atm water resistant 200m x x x x - Practical references The water resistant regularly examine, ideal-proves times per year. Many Uhrmacher offer this service for small money or even free of charge, if necessary in the framework to this examination also the seal are replaced Before use of the clock in the water it examines, whether crown and pushers locked correctly, if necessary bolted Do not operate pushers under water After unusually strong demand, i.e. Case, impact, the tightness for security to examine leave After contact with seawater the clock off with fresh water rinse, in order to avoid corrosion No extreme variations in temperature! From the Sauna in the ice water, from the sun in the cool sea extreme loads for the seal systems of the clock are direct Footstep the case of the cases - water - nevertheless: contact immediately to the watch maker!