Insulation testing and Loop testing of Thermocouples

[gravitate]

What I have been told to do is test a bunch of thermocouples at work. The equiptment I am using is shown here http://www.hkanswers.com/testing.jpg

These are my questions. I am testing them at 250v and if I get a reading less than 1 giga ohme or 1000 mega ohmes Then I take it as needing replacing. Does this mean that they are dangerous i.e. if you touch the stainless sheath you will get a shock? Also does this mean that if I do a continuity test from the wires to the thermocouple then I will detect a current?

Also Please can someone tell me how to do a loop resistance test? I have been told that when I do a loop resistance test I should get no more than 17 ohmes/m
Please could you describe how to do it in detail as I am not electrically minded and dont know any jargon.
Many thanks

 

[malcolmsanford]

Deja Vue ............?

 

[gravitate]

it is similar to the last one but this time with pretty pictures. I still dont know how to do a loop resistance test

 

[gravitate]

ps can I also use the equiptment in the photo above to do the testing? It is a Megger MIT400

 

[malcolmsanford]

The meggar will give you that 250v test on IR.

Being a non megger man and the picture is a little blured I can't see the scale this old age don't come on it's own it brings all it's friends along like dodgy mince pies.

But for the loop as you say set the meter to the continuity/ohms scale and then croc clip one on the green/white and the other on the blue/white and just read the screen

 

[gravitate]

great thanks for that. Regarding the loop resistance test then am I right by saying that turn it to the ohmes scale as you say then put the terminals on the wires that come from the thermocouple?