Foil test
Testing of ultrasonic baths
Information
A foil test
1
is recommended for testing ultrasonic baths. It is
to be conducted upon initial startup, and at regular intervals
thereafter (e.g. every 3 months). The frequency of testing is the
responsibility of the user.
The foil test is a simple procedure to demonstrate the intensity
and distribution of cavitation in an ultrasonic bath. To do so,
aluminium foil is stretched over a foil test frame. It is perfo-
rated or destroyed to a certain degree by cavitation, depending
on the duration.
For purposes of reproducibility, it is
important that the test
conditions remain constant:
• Fill level in the oscillating tank (²
ū
Ŷ
)
• Temperature of tank contents
• Degassing time, if needed (degassing 5 to 30 min. before
the test, depending on the tank contents)
Time may need to be extended with acidic cleaning solu-
tions.
• Frame
positioning
• Foil properties (thickness, surface)
• Sonication
time
• Concentration and type of ultrasound preparation
Foils can be archived in a suitable way (scanning, photos, etc.)
This allows the foils to be compared at any time. The perfo-
rated areas of all foils should have approx. the same
dimensions and distribution – the results are never identical.
A process validation, e.g. for the treatment of medical products,
can only be achieved by conducting regular foil tests.
To execute the foil test, different foil test frames FT can be
ordered from the manufacturer (for a fee). The foil test frames
are suitable for a wide range of tank dimensions. Aluminium
household foil is also required to conduct the test and is not
included in the delivery.
Film: http://bandelin.com/folientest/.
1
Investigations on test procedures for ultrasonic cleaners. IEC/TR 60886 (1987-03)
Fluid for the foil test
In order to obtain an adequately strong cavitation effect, the
surface tension of the water used must also be reduced for the
foil test with the help of surfactant preparations. We recom-
mend the following ultrasound preparations:
STAMMOPUR DR 8, STAMMOPUR R, TICKOMED 1,
TICKOPUR R 33, TICKOPUR R 30, TICKOPUR TR 7
If none of these preparations is available, a neutral or mildly
alkaline preparation that does not destroy aluminium may be
used. The preparation must be approved by the manufacturer
for use in ultrasonic baths.
939x GB/2018-09
1 / 2
Example
B Foil
test
Summary of Contents for Sonorex Super RK 31
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