losing faith in my test meter??

[jay_t]

I have a Di-log 9083p and it's giving some quite sporadic readings with Zs tests. I do maintenance within a school so i am based in the same building, each time i carry out a modification i do a Ze at the main incomer and it does vary a bit but i was changing a board last week and, just out of curiosity, i did 5 Ze tests within a few minutes and got varying results from 0.11 up to about 0.3.

Is this normal? I don't have a vast amount of field experience so i don't know, maybe it is?

My meter was calibrated 6 months ago and I have one of those credit card size calibration checkers and the meter checks out fine on that.

 

[Apache]

Dunno Jay - but I'll get in first

Should've bought a Fluke or Megger (delete as appropriate)

 

[binky]

some variance is not unusual but should be less than what you are seeing. When testing I always null leads first to ensure leads are OK, but the other trick is to ensure good connections, especially if using a croc clip, which comes with practice. The other posibility is that your batteries are getting low, or test gear is getting warm from repeat testing - I've had that problem before where a circuit I was testing was giving higher and higher Zs reading, but I had been testing circuits for about an hour.

 

[green-hornet]

Ze is one of the few readings that will change from time of day, so I would not place too much worry over them.

Remember to get an accurate reading all connections must be tight, and all parralell paths removed.

 

[Andy™]

Weather conditions will also effect reading slightly - the wetter the ground, the lower the readings may be. although i wouldnt expect it to vary by the amount your getting

 

[batty]

I had a 9083p which always gave different readings each time you tested in the end it had to go back to di-log as I was getting readings of .3ohm on a TT system and meter was faulty. I now have a fluke 1652 which gives constant readings the same each time you test.

Batty

 

[Andy™]

I had a 9083p which always gave different readings each time you tested in the end it had to go back to di-log as I was getting readings of .3ohm on a TT system and meter was faulty. I now have a fluke 1652 which gives constant readings the same each time you test.Batty

obviously a different fluke to what ive used in the past... i was normally lucky to get a similar reading twice!

 

[batty]

obviously a different fluke to what ive used in the past... i was normally lucky to get a similar reading twice!

Take it you are a megger man then.

 

[Andy™]

Take it you are a megger man then.

yes, and it would appear that over half the members on this site are as well

clicky

 

[batty]

yes, and it would appear that over half the members on this site are as wellclicky

But the other half are flukers.

 

[Andy™]

Fluke is looking desperate though - even the vet has had to vote to get their numbers up!

 

[batty]

Fluke is looking desperate though - even the vet has had to vote to get their numbers up!

But he is a sensible sort of chap.

; \

 

[green-hornet]

Most of my testers in the past have been megger, so a few years back I bought the then new fluke 1652, good tester but I think I prefer the megger tbh