Rust on jaws of clamp meter

[k3iroll]

1- Is rust on the jaws of clamp meter normal?

2- How does it affect the measurement?

3- How to remove the rust? What product are you using?

[Fraser]

If steel is used for the core, it can rust. No doubt about it.

To clean it off just use ink eraser as that is more abrasive than a pencil eraser. I suggest you do not use more aggressive abrasive than this for minor corrosion.  In serious corrosion cases you could use a very fine 'wet & dry' abrasive paper  of >1000 grit. Let the clamp peter clamp down on it and then gently pull it back and forth through the jaws. Clean the jaw faces with IPA to remove and grit and residues.

Whether the mild oxidation actually has a negative effect on the clamps performance ..... I doubt it, but have no experience of such with clamp meter designs.

Aurora

[k3iroll]

I believe all clamp meters are using steel core in order to produce electro-magnetic right?

How do you maintain the bare metal surface of the jaw? Are you applying inhibitor oil, or it is being plated properly?

[Stray Electron]

  I've had a couple of clamp on amp meters that I picked up surplus that had a lot of rust on them. I checked them then cleaned off the rust and checked them again and got the same readings so I don't think rust (a reasonable amount) affects them.

   CLR cleans rust off pretty well but today I'd try one of the rust removers that leaves a phosphate coating on the steel.