Why can an electron go through PVC insulator

[thomasj]

I connected a PVC insulated alligator clip test lead to a 12V (give 20V) DC power supply positive terminal and a multimeter. After that I connected an other one to the multimeter ground, and a third one to the power supply negative terminal. I turned the multimeter to DC V measure mode.
When I keep the two free alligator clips in my left and right hand, the multimeter show voltage. At the not insulated part of the clips I can see approx. 18.5-.8V but I understand this because electrons can go through my body.
But if I keep the insulated part of those clips, I also can see voltage which depend on how strong I press the clips. It can go to 3-4V which is significant leakage.
But if I keep and press the wires right below the clips, no leakage. Wires also PVC insulated and my multimeter can measure 100uV precision. I cannot keep strong enough to see any extra voltage. (On high precision mode multimeter always show 1-2mV.)

 

[anorlunda]

If the voltage was higher, that would be dangerous.

I'm having trouble visualizing what you are saying. Can you draw a diagram? Photo it and post the photo using the UPLOAD button.

 

[thomasj]

As I wrote, voltage was 20V DC. Not dangerous.
I cannot make photo but I wrote what I did step-by-step. There was just a 20V DC supply, a multimeter and me in the circuit. Oh, and 3 test wire with alligator clips on both end. That's all.

 

[The Bill]

I think what anorlunda is getting at is that you seem to be using a non-standard definition for the word "keep" in your original post. Non-standard to the extent that I really don't know what you meant, exactly.

 

[davenn]

Hi Thomas,
Welcome to PF

I cannot make photo

why not ? ... you have a mobile phone or other camera ?

but I wrote what I did step-by-step

Which, unfortunately is not entirely clearWe really need to see what you are doing so that there is no confusion

We know there is a PSU, a meter some wires and clips and your hands/fingers
we are not exactly sure of the connection combinations you describeDave

 

[Asymptotic]

I connected a PVC insulated alligator clip test lead to a 12V (give 20V) DC power supply positive terminal

As I wrote, voltage was 20V DC. Not dangerous.

What is a "12V (give 20V)" power supply?

As others have said, a drawing of what you are describing would clear up a lot of ambiguity, but if my mental picture is correct, then you have the meter (+) lead connected to power supply (+) terminal, are holding the meter (-) lead in one hand, and in the other hand a lead connected to power supply (-) terminal. In other words, a series pair consisting of a voltmeter, and your body is connected across the DC supply.

Setting aside for a moment that connecting a voltmeter as though it were an ammeter is odd, consider what a capacitor is - two conductors with a dielectric between them - and how this relates to your observations.