PASCO WA-9899 Ripple Tank System - Manual (Page 6)

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R i p p l e T a n k S y s t e m A b o u t t h e E q u i p m e n t
6
tank on a smooth, level surface. If you are going to use the light source, screw the rod into
the threaded hole near the midpoint of the top of the back edge.
To attach the reflector and projection screen to the tank, unfold the screen assembly and
put the reflector between the two front legs. Angle the reflector upwards and guide the top
edge so that the three holes fit over the pegs that are at the back edge of the tank. Next,
raise the projection screen to the vertical position and attach its Velcro® ‘loop’ material to
the strip of ‘hook’ material under the front edge of the tank.
Apply Surfactant Before putting water into the ripple tank for the first time, pre-
pare the foam beaches, barriers, and refractors with a drop of surfactant (a nonionic wet-
ting agent). The surfactant helps to avoid problems with the surface tension of the water.
Put a single drop of surfactant from the small plastic bottle onto the end of one finger, and
lightly rub your finger along the foam beaches. Use a single drop of surfactant to very
sparingly coat the large flat surfaces of the three refractors and the front surfaces of the
straight and curved barriers.
Level the Ripple Tank When you are ready to add water to the tank, squeeze the
sides of the tube clamp to close the clamp. Use the beaker to add a small amount of water
to the middle of the tank so that the water forms a circle about 10 cm in diameter. Adjust
the feet on the legs until the circle of water stays in the middle of the tank and does not
move toward any side. (An alternate method for leveling the tank is to add about 800 mil-
liliters of water to the tank. Measure the water depth at three of the four corners of the tank
and adjust the feet on the legs until the depths are the same.)
Dampen the Foam Beaches To reduce the problem of surface tension, let the
foam beaches soak up some of the water. After putting about 800 milliliters of water in the
tank, press down on the foam and then release the pressure so that water enters the pores
of the foam rubber.
Cleanup
Before emptying the tank, remove the projection screen and reflector. Fold the screen
assembly so the projection screen protects the reflector.
To empty the tank, place a container under the drain pipe and open the tube clamp. When
the water stops flowing, raise the corner of the tank opposite to the drain hole so the rest of
the water will drain out. Leave the tube clamp in the open position.
Be careful to remove as much water from the foam beaches as possible. Press with your
thumbs against the foam to squeeze the water out. Next, press a rolled-up towel onto the
foam beaches to soak up any remaining water.
Completely dry the glass plate so that water spots won’t form on it. To clean the glass
plate or the reflector, use a soft cloth moistened with water and then dry with a clean
towel. Do not use soap or chemical cleaners.
Tip: Note that you only need to
apply the surfactant to the
beaches, barriers, and refractors
before using the ripple tank for
the first time, or it has been
unused for a long time.
Tip: Leave the tube clamp in the
open position after draining the tank
to avoid crimping the plastic tubing.