Robin 3050 DL Problems?

[optician]

I'm hoping someone out there will be able to help me.

I have recently had the above tester ( Insulation & continuity) calibrated and the other day decided to change the batteries, (wasn't convinced of the readings I was getting)

Straight away all readings were different, I was happy, however.

I've been testing 3 different ring circuits T&E 2.5/1.5 and the end to end results are puzzling me, or am I being picky? (new spark)

Sample of results

P-P .20 .19 .18 .10 .09 .11 .20
N-N .20 .19 .18 .09 .09 .11 .22
E-E .44 .44 .43 .31 .30 .30 .47

Am I correct in thinking the E-E should be approximatly 1.67x the P-P& N-N

So I got a newish 2.5/1.5 roll of cable and got P-P .32 N-N .32 & E-E .62!!!!!

Am I too picky or has any one else had a similar experiance? Any advice greatly appreciated

 

[scotsparky]

Looking at the results they seem fine. dont worry about the little flucutions in readings that can be the probe,clamp contacts

As for the 1.67 rule yes that will give you a general idea of what your figure should be but dont rely on it totally.
Just worked out the resisitance of the cable using your 1.67 rule and its meant to be 0.53 so i wouldnt worry about your reading being 0.62 is very close.

 

[optician]

Since noticed on nulling tester and checking, that the instrument reads -0.0 which means it is nulling to below zero! so now I do not null and after taking off the restance of the leads/tester the readings are correct, happy days.
Just need to get the tester fixed now.

 

[Spudnik]

Since noticed on nulling tester and checking, that the instrument reads -0.0 which means it is nulling to below zero! so now I do not null and after taking off the restance of the leads/tester the readings are correct, happy days.
Just need to get the tester fixed now.

Must admit, mine does the same so it may not be a fault.

However, it doesnt do it all the time and generally it zeros out normally.

Let us know how you get on if you do send it in for repair.

 

[optician]

Jason; I found I had a problem with the null because I half mentioned the -0.0 to the guy who calibrated it originally, when I took it back to check the discrepencies on the lower ohm readings I mentioned at the beginning of this thread.
Since then my meter seems to auto null with a -0.0 all the time I have calculated that it actually under reads by 0.15 ohms, so I don't auto null any more.
The guy that found the problem calibrated another 6 of the same meters that day and only one with a similar serial number had the same problem.
He is contacting fluke to find out what to do. Will let you know.

 

[Spudnik]

Jason; I found I had a problem with the null because I half mentioned the -0.0 to the guy who calibrated it originally, when I took it back to check the discrepencies on the lower ohm readings I mentioned at the beginning of this thread.
Since then my meter seems to auto null with a -0.0 all the time I have calculated that it actually under reads by 0.15 ohms, so I don't auto null any more.
The guy that found the problem calibrated another 6 of the same meters that day and only one with a similar serial number had the same problem.
He is contacting fluke to find out what to do. Will let you know.

Thanks for that.

 

[optician]

got a reply from fluke, apparently you can get a -0.0 on autonull because of dirty contacts, either at the lead insertion or on the switch.
to correct it they need taking to bits and cleaning. great, then need recalibrating. I think I'm about to have an arguement, as they have already calibrated it, when it was faulty!

 

[Spudnik]

Thanks for the info.

Must admit, i feel the same as you as mine were done in March.

As you say, time for a phone call..

Cheers
J

 

[optician]

Happily, the technician has cleaned my switches and now it works well, I can still get -0.0 but it isn't as far out in accuracy terms. as it was and it isn't every time I auto null. Happy Days
Dave.