Protecting Sensitive electronics from Outside interference is the main crux of Multimeter Shielding. Without proper RFI/EMI protection you risk the possibility of a flawed test reading and a non accurate test outcome as a result.
Unfortunately the majority of multimeters both CHEAP and EXPENSIVE no longer ship with any shielding. As cost savings and bottom lines become the go-to in business, shielding has all but disappeared in the world of multimeters. It's a paradox because without proper shielding in your multimeter, electromagnetic interference (EMI) Radio Frequency interference (RFI) can greatly impact your test results!
A simple and quick Shielding hack costs pennies and actually can improve your multimeters performance,
You can easily purchase some Copper Foil Tape from major online retailers such as Ebay or Banggood. It's cheap too.. starting around 2$
Simply portion to fit your multimeter and you'll have a quick and simple , yet effective Faraday cage! It's a cheap NO-Brainer way to beat those no-shielding blues and maintain accurate readings with your multimeter!
Of course Aluminum foil will also do but Copper is the most reliable metal in EMIshielding because it is highly effective in attenuating magnetic and electrical waves. From hospital MRI facilities to basic computer equipment, use of copper in RFI shielding is used because its effective!
EMI shielding materials
Materials used for EMI shielding need to be electrically conductive, so they’re almost exclusively metallic.
Copper is a common material for EMI shielding due to its excellent conductivity, versatility, and the wide variety of alloys that can be used.
Nickel silver (which ironically has no silver in it, but is instead a copper-nickel alloy) is particularly desirable due to its corrosion resistance.
It can also be used for shields that will be soldered on, and applications where ferromagnetic materials aren’t allowed.
Galvanized steel, which is steel coated in zinc to reduce rust, is also a useful EMI shielding material, as it’s cheap, durable, and effective.
Aluminum can also be used for EMI shielding to significant effect.
It’s not ferromagnetic, so it can be used in rooms that can’t have magnetic materials, it’s very conductive, and it’s also very strong for its weight.
Graphite is the only non-metal that is electrically conductive. You’ll often find it in EMI shielding products that can’t have metal in them.
Faraday Cage
The simplest form of EMI shielding is a conductive metal housing that forms a continuous enclosure of shielding around a protected device.
The resultant continuous housing is known as a Faraday shield. SO by simply adding a copper surround to the innards of your multimeter you are in effect creating a Faraday cage for your instrument!
As you can see, adding a simple form of EMI Shielding to your multimeter is inexpensive and can greatly improve the accuracy of your readings. So, what are you waiting for..? Pickup some Copper Tape Today and fight those nasty shielding blues while improving your test results!
Oh thanks Darren. That's a great idea. Good article!