Multimeter test leads how-to cleaning to avoid conductive contamination

[Kiriakos GR]

Over time all multimeter tests leads over their body and cables they get dirty, black spots and grey smooches those are signs of conductive contamination.

Under a microscope all this contamination now it is visualized and the true picture this is millions of conductive particles.
They could be in the form of metallic particles dust this mixed with oil from your own hands, or even worst them be mixed with lubrication oil for heavy machinery.

Another contamination source this is carbon brushes used in electrical motors, also this dust it is highly conductive.

When conductive contamination is high, tests leads isolation properties gets really low and hazard of electrocution get high.

I would suggest if you’re electrical applications are several, it is wise having several pair of test leads.
One will be kept always clean and this will serve for Mains and three phase voltage measurements’ or up to 1000V measurements, and another test leads pair this for regular troubleshooting and electronic components measurements’.


Cleaning
The exterior of the test leads should be cleaned with a good bath in soap water, and after drying (over night) a soft cloth moistened with isopropyl alcohol, this will remove any remaining contamination.

Cleaning of test leads metallic outer surface this is possible also by a soft cloth moistened with isopropyl alcohol, but also there is and a second suggestion for test leads them not looking as new any more.
There is available a small pen this loaded with fibber glass brush, this removes any carbon deposits’ over metallic surface, and also removes oxidation with out damaging any special coating over a metal surface ( For example: gold plated contact points).   

In conclusion take good care of your test leads and any of your test leads accessories, they are your shield against electrocution, and never forget this detail.