4
www.phywe.com, © All rights reserved
11260-
02 / -88 / 2516
4.1 Putting the ripple tank into operation
First connect the connecting socket (
) of the ripple tank via
the provided power supply to the mains. The LCD screen
lights up and the ripple tank is ready to use.
4.2 Filling the wave tray
First, the empty wave tray has to be placed on the ripple
tank. Afterwards, it can be carefully filled with water. The
wash-bottle supplied can be used to fill the wave tray. Fill the
tray about three quarters high. After this, to have reflection of
water waves at the sides suppressed, moisture the whole
side-foam with a finger so that water can wet it.
Use the adjusting screws (
) to align the wave tray horizon-
tally. To do so, we recommend that you look flat across the
water surface and use the height of the water level at the dif-
ferent sides of the tray as reference. Now use the screws to
bring the tray to about the same height on all sides and so to
a horizontal position.
When lifting the filled tray, the water tends to slop! Pay
attention that no water enters the device.
We recommend using the wash-bottle or e.g. a sponge to
finally remove the water while the wave tray is still resting on
the ripple tank.
4.3 Cleaning
The cover plate and the wave tray of the ripple tank consist of
acrylic glass. Please perform cleaning of the cover plate and
the wave tray with suitable (i.e., non-abrasive) tissues without
aggressive chemicals added.
4.4 Generation of circular waves
Fix the holding rod (
) to the inte-
grated generator (
) and bring it to the middle of the wave
tray. Turn the clamping screw on the generator until the plug
is dipped into the water in the wave tray. Set to continuous
light, to a frequency of between 5
Hz and about 20 Hz and to
a small amplitude (1 or 2). Prepare the observation surface
by placing a sheet of white paper on the drawing table situ-
ated over the wave tray. Darkening the room could be useful
for better visibility of the wave image.
Should the wave image be distorted or unclear, vary the fre-
quency
f
and/or the amplitude until a wave image is obtained
that is similar to that shown in Fig. 7.
Fig. 7: Circular waves generated by the plug-shaped exciter.
4.5 Generation of flat waves
The generation of flat waves is somewhat more difficult, be-
cause it requires an exact alignment of the wave tray with the
slide used. It could be necessary to add 1 to 2 drops of a
soap solution to the water for better wetting. Do not exceed
this amount, however, as then turbidity and foaming would
occur and cause deterioration in the quality of the image.
Fix the holding rod with slide to the exciter and bring it to the
lower end of the wave tray. The wave tray must now be cor-
rectly adjusted, as the slide must be exactly evenly immersed
into the water. If this is not done precisely, the wave image
will be distorted and unclear. See the information given on
the correct adjustment of the wave tray in section 4.2
”.
The slide must also be set to be horizontal. Therefore, fix it
as horizontally as possible to the integrated exciter and
tighten the clamping screw on the exciter further until the
slide is held slightly above the water surface. Use the water
surface as reference to adjust the slide to the horizontal posi-
tion. Afterwards, turn the clamping screw on the exciter fur-
ther until the slide is dipped into the water (abou
t 1 to 2 mm).
Set a frequency between 18
Hz and 25 Hz and choose a
small amplitude as well as continuous light. A wave image
should be obtained that is similar to that shown in Fig. 8.
Fig. 8: Flat waves generated by the plane exciter.
Should the wave image be distorted or unclear, vary the fre-
quency, the amplitude or the immersion depth. When no im-
provement in the wave image results, it could be possible
that the slide is not correctly adjusted and therefore does not
dip evenly into the water. In this case, align the slide as de-
scribed above.
4.6 Usage of the stroboscopic light
The use of stroboscopic light is only instructed in those indi-
vidual experiments in which it is required to reach the ex-
perimental target. All other experiments should first be car-
ried out without stroboscopic light because stroboscopic illu-
mination considerably changes the impression of the image,
partially. Interference patterns can be far more impressively
seen when continually projected than when under strobo-
scopic illumination.
In this context it must be considered that for continuous light,
the human eye is only capable of recognizing the wave im-
age in the lower frequency range. Because of this, we rec-
ommend that only frequencies of up to about 30
Hz be used
under continuous light. Stroboscopic light should be used
with shorter wavelengths (higher frequencies), so that wave
propagation is slowed down and made visible to the human
eye.
5 NOTES ON OPERATION
This high-quality instrument fulfils all of the technical re-
quirements that are compiled in current EC guidelines. The
characteristics of this product qualify it for the CE mark.
This instrument is only to be put into operation under special-
ist supervision in a controlled electromagnetic environment in
research, educational and training facilities (schools, universi-
ties, institutes and laboratories). This means that in such an
environment, no mobile phones etc. are to be used in the
immediate vicinity. The individual connecting leads are each
not to be longer than 2 m.
Attention!
