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10-1 Water Resistant Tester
This tester is used to determine the locations of water penetra-
tion in watches that have been judged to have defective water
resistance.
Thus, this instrument is also useful since it is able to determine
what part should be replaced in the case of defective water re-
sistance.
Tool used
1) Place water in the cylinder and cover the cylinder with the
watch suspended inside. (At this time, the watch should be
suspended in the space above the water.) The air pres-
sure and water pressure in the cylinder at this time are 1 bar,
and the air pressure inside the watch is also 1 bar.
2) Pressurize the inside of the cylinder to the pre-
scribed pressure. (The cylinder should be pres-
surized by 1 bar for every 10 meters of water resis-
tance.)
3) Once the cylinder has been pressurized, leave
the instrument for 3 minutes. Although the in-
side of the cylinder is pressurized at this time, if the
water resistance of the watch is satisfactory, the
pressure inside the watch will remain at 1 bar even
after 3 minutes. What is more, if the water resis-
tance of the watch is defective, the inside of the
watch will also be pressurized with the air pressure
and water pressure inside the cylinder.
4) Lower the watch into the water after 3 minutes
have passed, and secure it in that position.
5) Gradually reduce the air pressure in the cylinder.
If the water resistance of the watch is satisfactory, there
will be no change in the watch even though the water
pressure has lowered.
If water resistance is defective and the inside of the
watch is pressurized, the air pressure inside the watch
will decrease accompanying the decrease in water
pressure causing air to be released from the watch.
As a result, many bubbles will appear from the lo-
cation of defective water resistance. (Fig. 10-1)
This makes it possible to determine the location of the
leaking.
In this case, although small quantity of bubbles may appear from the gaps between the case and
buttons, case and bezel and so forth, this is the result of air trapped in the gaps being released as
bubbles, and does not indicate defective water resistance. (Fig. 10-2)
NO.
Code No.
Tool name
1
1904 5225 Water resistant tester
Water resistant tester
Many bubbles (leaking point)
Small quantity of bubbles
Fig. 10-1
Fig. 10-2