Ultrasonic baths are a great way to clean items or to dissolve solids into solvents fast.
How to perform the foil test
- Fill the bath with water to the usual fill line.
- Turn the ultrasonics on and allow the bath to degas (usually requires 30 minutes to 1 hour, but check the user manual for your bath)
- Cut a piece of Aluminium Foil to fit your bath
- Using tweezers, lower the foil into the water until it is just above the base of the inner basket. Make sure your hands don’t enter the liquid.
- Hold the foil in the water for a set period of time – you can set this yourself as long as you use the same time period every time. Around 30 seconds should be sufficient.
- Remove the foil and evaluate the markings;
For larger baths or a more in depth assessment, you can use a cross grid of tape to hold foil strips at all different points within the bath, allowing you to cover a greater area easily.
Intepreting the results
The foil test is qualitative rather than quantitative, but it can provide a good indication over time on whether your ultrasonic bath is still performing well. Performing the test once a month and keeping the foil sheets afterwards lets you monitor the bath over time.
The distribution of the holes is a good indicator of the distribution of the ultrasonic energy within the bath – you can quickly tell if there are any areas where the power is less strong, which could indicate a failed transducer.
Keeping variables constant is the most important point to remember when performing the foil test in an ultrasonic bath – temperature, ultrasonic power, foil position, water depth and the foil used should all be kept the same in order for you to fairly compare results.
Contact us if you have any questions;