|Yverdon-les-Bains, Switzerland - 2002
How they obtained the blur effect
the saturation of the air with moisture, which produces
the visible mist effect, depends on a number of physical
these parameters include the speed and direction of the
wind, the environmental temperature and the
atmospheric humidity :
- the higher the temperature, the greater the amount of
moisture required to produce the necessary degree of
- when the air has a moisture level of, for example,
75 percent, the desired effect can be achieved by the
addition of only 25 percent.
- the volume of the space determines the output quantity
necessary for the saturation of the air with moisture.
in calm (windless) conditions the volume corresponds
to the size of the space. in windy conditions, however,
the determining volume is proportionate to the amount
of air moved by the wind through the specific space.
thus it increases with increasing wind speed.
- since mist hangs in the air, it moves in the direction of the
wind. starting at the point where the water leaves the jet,
a white stripe becomes visible. as soon as the air is no longer
saturated with moisture, this white stripe disappears.
at low temperatures with simultaneous high air moisture,
the stripe is virtually always visible. when the conditions are
reversed, it disappears almost immediately.
- putting the cloud into operation under consideration of all
these meteorological conditions is a highly complex technical
proceeding. appropriate adjustments can be made on various
levels, e.g. the placement of the spray mechanisms,
the number of jets, planning of different spraying areas.
the optimisation of these measures is carried out with the help
of a computerised weather station that supplies the necessary
nformation about the relevant parameters.
this information is analysed by the computer and subsequently
used to determine the adjustment of the spraying on the basis
of conclusions reached in connection with tests carried out the