Foil test procedure

Items Required

• Aluminium foil MED1002 (0.018mm by 20mm soft temper)
• Metal paper clips (x 9)
• Self adhesive tape (Clear tape.)
• Stop Watch - Method of timing de-gas and test period
• Test results sheet

Test Procedure
The foil test is the simplest method of measuring the ultrasonic activity over the whole of the tank; depending on model under test, between one and nine foils are suspended from the tape. The paper clips are used to weigh down the foils. Ø All tests are carried out with the basket removed.

The tank must be filled with clean water at or near the operating temperature of 40OC. Detergent is added but this must be a constant as it can effect the erosion.

The timer is then set for 10 minutes; this period is called the de-gas period. Water from the tap or other source has a high quantity of dissolved gases in it. For the Ultrasonic energy to be efficient most of the dissolved gasses must be removed. Just running the ultrasonics for ten minutes will remove 99% of these gases and will enable consistent results for the foil test.

The foil is cut or torn to a length that is 50mm longer than the overall depth of the tank. This leaves enough for a paper clip to be pushed on to one end and rolled two turns.

The foil is then lowered into the previously de-gassed water until it just touches the bottom of the tank and then it is raised, so it is not touching the base, but not more than 10mm above the bottom. The other end is then attached to the tape suspended across the top, making sure the foils hang vertically.

This is repeated with all the foils.