How does a IR Tester work?

[semaphore]

Hi guys, 1st post, so please be gentle with me!
I know how to use one but does anyone know how an IR tester actually works?
I'm using a Megger 1502 and testing at say 500vdc does it actually apply 500vdc all the time you press the button and deliver 1mA for the whole time?
And how long should you press it for?
I've tried to get some info but it doesn't seem to answer these questions.

 

[ezzzekiel]

will depend on the meter how the test button is to be applied.

And its basically just a calculator that uses ohms law

 

[Addlight]

As ezzzekie says, probably depends on your meter - but also on battery. When you press the button you deliver the full Vdc for as long as your battery holds up - I dont think it pulses the voltage.

From experience I'd recommend using 250Vdc first - just to get lay of the land, see if there's anything still showing up after you've disconnected everything, taken lamps out, etc.

 

[ezzzekiel]

From experience I'd recommend using 250Vdc first - just to get lay of the land, see if there's anything still showing up after you've disconnected everything, taken lamps out, etc.

yep - my method also

 

[oldtimer]

If you think about it in plumbing term then an IR test is like a pressure test

Say for example pipework needs to carry 1 bar pressure so you test it with 2 bar pressure and it holds so that means the pipework can carry the operating pressure.

Now take an electrical circuit......................................you get the rest

 

[ringer]

Hi guys, 1st post, so please be gentle with me!
I know how to use one but does anyone know how an IR tester actually works?
I'm using a Megger 1502 and testing at say 500vdc does it actually apply 500vdc all the time you press the button and deliver 1mA for the whole time?
And how long should you press it for?
I've tried to get some info but it doesn't seem to answer these questions.

have you tried emailing Megger customer support?

 

[johnboy6083]

oldtimer, some people still call it a pressure test, when type testing switchgear, and hv cables ect!

 

[semaphore]

ringer,

Thanks, I took your advice and emailed them but got no reply yet.
I've done a bit of googling but no joy.
An electronics guy told me I should be reading the value after applying the test voltage for 1 minute?
If you short out the leads and press the button, I imagine the meter must detect it and cancel the test, otherwise a potentialy unlimited current would flow? I would therefore assume there is some kind of shunt resistor in the meter. I heard that if you hold the probes tightly and press the button you don't feel a shock, it's probably and old wives tale but I'm too chicken to try it.
It's this kind of stuff I don't understand.

 

[xraytek]

I heard that if you hold the probes tightly and press the button you don't feel a shock, it's probably and old wives tale but I'm too chicken to try it.

Well you might just get a little tickle

 

[Addlight]

Or, if you get bored you can try this ...

[ame="http://www.youtube.com/watch?v=8whQKK4Q-u8&feature=related"]YouTube - IDIOT MEGGERS HIS EARS[/ame]

Endless fun at home on an wet evening ...

[ame]http://www.youtube.com/watch?v=dP7MxTYzKO4&NR=1[/ame]

 

[Graeme Harrold]

MEGGA................

Used to have tons of fun charging up capacitors with the wind up model and throwing them to unsuspecting victims

 

[Jimmy Boy]

Now that's funny.......

 

[ut1dot]

When I was taking 16th edition a few years ago the tutor told us how they work. But all I can remember is it measures capacitance and coverts it to ohms.

Found this hope it helps.