Magnet Inspection, Cleaning, Checking for Strength and Contamination Removal advice.

INSPECTION AND CLEANING

Processes, products and levels of contamination vary from industry. Therefore, there is no set timescale for inspecting and cleaning of the magnets. However, magnets operate more effectively when they are clean. It is therefore up to each company, given their expected levels of contamination, to decide when they should be cleaned. A regular rota should be set up for personnel to inspect and clean the magnets. Ideally this will be at least after each different process. This will help in identifying problems up the process line, if some processes show more collection of contamination than others.

STRENGTH TESTING

We supply magnets according to strength required. We can also issue a certificate for this if required. There is no set time when the strength of magnets should be checked. It is up to the company to decide. The magnets are permanent and should not lose their strength unless exposed to heat, shock or vibration. Magnets should not be heated above their heat resistance. The heat resistance of the magnets will have been specified when ordered. As a general rule, however, an annual inspection should suffice.

To test the strength, you will require a gaussmeter that ideally shows maximum readings. Using the probe on the surface, the magnet strength varies along the tube, so it is important to find the highest reading, which can sometimes take 10-15 minutes.

CONTAMINATION REMOVAL CAPABILITIES

In terms of collection, powerful magnets can collect contamination particles as small as 30 microns. However it is important to bear in mind that not all 100% contamination will be removed for various reasons, such as shear rates, flow dynamics, or the possibility that small particles can be trapped within the product, thus preventing removal. However the higher the strength of the magnets, which we can manufacture up to 12000 gauss, the more likely it is that the particles will be attracted and held to the magnets in the product stream.