This test checks to make sure that the ultrasonic activity in the tank is even and appropriate, and that instruments within are being cleaned effectively.
HTM 01-05 Ultrasonic Activity Test
The test is performed by testing that the transducers beneath the bath are working efficiently, and that instruments are being processed correctly during the cycle no matter where they are placed within the tank.
Commonly known as the ‘Foil Test’ or ‘Foil Ablation Test’ as the method usually involves using strips of foil.
There are other methods of performing the ultrasonic activity test such as wand meters, however using foil strips evenly spaced throughout the tank remains the most economical and repeatable method.
What Equipment and Materials are Required?
|D = Day | W =Weekly | Q = Quarterly | Y = Yearly | CP(D) = Competent Person (Decontamination) | ENG = Engineer|
When is it Performed, and by Who?
|Document||Specific Title||Reference||Installation & Commission||Periodic Testing|
|HTM 01-05||Ultrasonic Activity Test||15.6||
What is the Procedure, and Pass/Fail Criteria
|Document||Test Procedure||Pass or Fail Criteria|
1. Measure the depth of the empty tank.
2. Cut nine strips of foil that is 120mm longer than the depth of the tank.
3. Prepare the ultrasonic cleaner for use as the operator would routinely by adding water and the appropriate detergent.
4. Degassing should also be performed.
5. The ultrasonic cleaner should achieve all the necessary start-up requirements set out by the manufacturer, and should be ready as if about to process loads as normal.
6. Using the tape, place a 3x3 grid across the top of the tank. The tape should be positioned evenly spaced.
7. Number each of the nine intersections. The intersections should be numbered exactly the same each time the test is carried out so that test results can be compared at a later date if necessary.
8. Take each foil strip and measure 120mm along the length.
9. Roll up this length to weigh the strip in the solution. Each strip should now be the same length as the depth of the tank.
10. Measure 10mm from the other end of the foil strip and fold into an ‘L’ shape.
11. Attach a foil strip to each of the nine numbered intersections. The rolled up end should be facing downwards.
12. The manufacturer should provide a length of time to operate the cycle for this test. This can vary between 30 seconds and 10 minutes. If there is no timer in the unit, use a stopwatch for timing.
13. Once the cycle has completed carefully remove the foil strips and blot-dry.
14. The numbered position of each strip should be noted when filing the strips in the ultrasonic cleaners log book
Performing the test on a smaller ultrasonic cleaner
Although nine strips of foil are specified in the HTM 01-05 test procedure, Isopharm have found that this can be too much for smaller tanks.
If the test is being performed on an ultrasonic cleaner with a tank 1.5 litres or less, Isopharm recommend that the following amendments are made to the steps in the HTM 01-05 test procedure:
2. Cut four strips of foil that is 120mm longer than the depth of the tank.
6. Using the tape, place a 2x2 grid across the top of the tank. The tape should be positioned evenly spaced.
7. Number each of the four intersections. The intersections should be numbered exactly the same each time the test is carried out so that test results can be compared at a later date if necessary.
11. Attach a foil strip to each of the four numbered intersections. The rolled up end should be facing downwards.
The test is a pass if all strips of foil are eroded uniformly.
The heaviest erosion should typically match the position of the baskets normally placed in the tank when processing loads.
The erosion pattern should be consistent with each test carried out. Deviation from normal erosion patterns may indicate transducer failure.
The test is a fail if no erosion takes place or if there is significant change in the erosion pattern when results are compared with previously undertaken ultrasonic activity tests.