Chapter 4
ACCESSORIES FOR ASTRA ULTRASONIC UNITS
The following accessories are available for the ultrasonic units on request:
- Stainless steel lid.
Use the steel lid to close the ultrasonic tank.
- Take great care with the condensation produced through the heating steam inside the lid since,
during opening of the latter, condensation liquid could drip onto the electrical parts such as the
socket. The lid therefore has to be raised vertically allowing the condensation to drip only inside the
ultrasounds tank.
- Rectangular basket in stainless steel mesh.
The stainless steel mesh basket is a very useful accessory in that it allows washing of the objects to be optimised and
the objects themselves to be drained inside the tank after washing. By folding the handles, the basket can be suspen-
ded with precision over the tank.
- Glass beakers.
Special beakers with an adjustable black rubber support ring are available. They are used to save detergent liquid whe-
never small quantities of objects are to be cleaned, or if washing is to be performed with a detergent solution in a beaker
and rinsing simultaneously in another beaker. They are also used to wash objects with particularly aggressive solutions
which must not come into direct contact with the steel tank.
- Stainless steel beaker-holder.
The perforated lid is used to support the beakers during washing. Remember to adjust the support ring of the beaker so
that the bottom of the beaker is always in contact with the liquid of the tank, but at the same time does not come into
contact with the bottom of the steel basket.
- Small round basket
In stainless steel mesh to be inserted in the beaker for washing small parts.
Small stainless
steel immersion
basket
Chapter 5
CLEANING WITH ULTRASOUNDS
What are ultrasounds?
Ultrasounds are vibrations of a material medium which are similar to sound waves, but with frequencies which are too
high to be audible to the human ear. The frequency limit of human hearing ranges from around 10 Khz to approximately
18 Khz. The audible frequency limit decreases with the increase in age. More particularly ASTRA ultrasonic cleaning units
operate at a frequency of as many as 45 Khz, i.e. at a frequency much higher than the audible one. All the ASTRA units
consist of an ultrasounds generator and one or more piezoelectric transducers (according to the model) which are atta-
ched to the outside base of the tank in stainless steel containing the washing liquid. The electronic generator produces
a continuous signal at a frequency of 45 Khz, and pilots the piezoelectric transducers which transform the electrical signal
into a mechanical vibration. This vibrational energy is transmitted to the liquid in the tank at the frequency of 45,000 oscil-
lations per second. These pressure and vacuum oscillations create an enormous quantity of microbubbles in the liquid
which, by imploding in extremely rapid succession, create enormous impact energies between the detergent liquid and
the surface to be cleaned. This is known as "cavitation" and provides an efficient and safe cleaning method in less time.
18
Stainless
steel rectangular
basket
Stainless
steel beaker-holder
Glass beaker
and plastic beaker
Stainless
steel lid