TMK TEM1555B Insulation tester

[Old Sparky]

I bought one of these at last year's NVCF, then obtained some new test leads from CPC for it, but have never seriously used the instrument.  Reading the instructiions I see that it performs the same functions as a megger, so it will no doubt be useful, especially to test the insulation of things such as mains transformers, etc., though I'm a bit wary of using it on either of the two pre-war radios which are awaiting my attention.  What are other members views on this?

[Refugee]

The test currant is low enough that it aught not to do any harm.

[raylec]

You should be ok,but dont use more than 500V on old equipment. Although the current is small its the voltage that damages insulation. If the radios have 2 core lead, then its a good idea to check insulaton. Chassis are not normally earthed to mains,connecting an earth, even through the earth socket,will stress the insulation of the transformer,so its important to have good insulation here.