Most accurate Insulation Resistance tester out there?

[allybally]

I'm just wondering is there a really accurate IR tester on the market

many thanks

 

[Pete999]

Well all my test instruments, when I was bust working were Fluke, bu IMHO I think they are all pretty much a mchness, others may not agree but that's what I have found, for what it's worth.

 

[allybally]

Sorry I choose the wrong word to use, not accurate, I want one that goes lower that 0.00 M ohms, to more decimal places

 

[Pete999]

Use an Ohm meter then

 

[davesparks]

You don't want an insulation resistance tester for testing such low impedances!

 

[SJD]

I think perhaps the problem is that a typical MFT measures continuity up to about 2000 Ohm, and measures IR with a readout from 0.01 MOhm to maybe 199 MOhm or 1999 MOhm. My KT64 does this.

So there is a gap, from 2kOhm to 10kOhm, where you can't measure the resistance with a MFT, other than to say it is between these values. I really wish the manufacturers had thought about this, it can be useful to measure in this range when fault-finding sometimes.

 

[davesparks]

MFTs are not designed as a fault finding tool but as an all in one soloution for carrying out the standard installation tests in the regs.

 

[SJD]

MFTs are not designed as a fault finding tool but as an all in one soloution for carrying out the standard installation tests in the regs.

I know, and I also have in my tool bag both a multi-meter and a clamp meter. I just think it is a pity the MFTs were designed to do no more than the standard tests. Another example, my KT64 has a volts range, but below 25V, it just displays "<25V", I don't believe it would have been too difficult to make it display lower values.

 

[Engineer54]

It would be helpful to know what you are intending measuring, that way you would get far more useful answers...

 

[allybally]

At the moment i use my fluke 1652 as a fault finder as well, but would just like a better value than 0.01M ohms so when I'm tracing I have an idea if I'm going the right way

thanks

 

[Engineer54]

At the moment i use my fluke 1652 as a fault finder as well, but would just like a better value than 0.01M ohms so when I'm tracing I have an idea if I'm going the right way

thanks

Then you'll need a multimeter, even a good budget job will normally do.... Oh, and for those weird phantom voltages that can at times throw you off course, an even cheaper analogue multimeter...

 

[GMES]

Yeah if money permits a good Avo and Analogue as above

 

[7029 dave]

I got myself an analogue IR tester, Duoyi dy3165 from china nice bit of kit.

 

[SirKit Breaker]

Get yourself a combined IR/Continuity tester. Does what it says on the tin.

 

[stevethesparks]

I find the Fluke 117 to be a decent all round electricians multimeter. Its also got a "LoZ" setting to help eliminate ghost readings. The volt alert isn't up to much (similar to volt stick) but can have its uses.

 

[davesparks]

Robin K3131DL is my long serving and trusty fault finding meter, I highy recommend them.

 

[ipf]

Get yourself a combined IR/Continuity tester. Does what it says on the tin.

Agreed.
As far as I'm concerned, that is one basic peice of kit for a qualified electrician. I find it baffling how anyone could be without it. MFT's came in as a handy, all-in-one method for testing and inspection, an ideal peice of kit for a 'domestic installer'....never had one and never will.
In general it's an IR/continuity tester, loop/rcd tester and multimeter for me. ... more obviously come into play, depending on the situation, earth leakage tester, tongue ammeter, etc, etc.

 

[shanky887614]

I find the Fluke 117 to be a decent all round electricians multimeter. Its also got a "LoZ" setting to help eliminate ghost readings. The volt alert isn't up to much (similar to volt stick) but can have its uses.

what is the LoZ setting?

 

[allybally]

what is the LoZ setting?

It's a way of eliminating Ghost Voltages, it put an impedance on the circuit and will show a true voltage, similar to an analog meter

 

[shanky887614]

It's a way of eliminating Ghost Voltages, it put an impedance on the circuit and will show a true voltage, similar to an analog meter

thanks, had a look at that fluke tester and when I get my ticket ill get one

 

[Geoffsd]

It's a way of eliminating Ghost Voltages, it put an impedance on the circuit and will show a true voltage, similar to an analog meter

It's the other way round.

Most multi-meters, and this one (Fluke 117) in normal AC voltage mode, have an impedance >5 Mega ohms.

In LoZ (Low impedance) it is only around 3 Kilo ohms and automatically ranges for AC and DC.

 

[tony mc]

Get yourself a combined IR/Continuity tester. Does what it says on the tin.

Must admit I have a few meters and the one I use the most is the Megger MIT 320 excellent bit of kit for IR testing but also has low Ohms and K Ohm setting which is good for fault finding IMO!!

 

[silver surfer]

Megger DLRO 10 HD goes to 4 decimal places for low resistance readings.

Megger LTW 425 goes to 3 decimal places for Earth Loop readings.

 

[Engineer54]

Megger DLRO 10 HD goes to 4 decimal places for low resistance readings.

Not exactly your normal common a garden low resistance meter though is it?? This is what is commonly know as a ''Ductor'' tester that applies a high current into the test piece via current and voltage probes (4 point contact probes)!! Oh and probably costs around the 2k to 2.5k quid mark...

Did i mention, it's also a totally inappropriate bit of test kit for measuring the resistance of circuit wiring to boot.....

 

[shanky887614]

there is no such thing as the most accurate insulation resistance tester, when its been calibrated there all the same, quality and reliability is what sets them apart

if they have same range that is

 

[davesparks]

Nonsense, just because a tester is calibrated it doesn't mean it is of equal accuracy to another calibrated meter.

I've got a calibrated vernier caliper and a calibrated micrometer, they measure the same thing but to different accuracy.

 

[Engineer54]

there is no such thing as the most accurate insulation resistance tester, when its been calibrated there all the same, quality and reliability is what sets them apart

if they have same range that is

Sure there is, ....it depends on the accuracy of the meter, generally the higher the accuracy the higher the cost!! lol!!

 

[shanky887614]

Nonsense, just because a tester is calibrated it doesn't mean it is of equal accuracy to another calibrated meter.

I've got a calibrated vernier caliper and a calibrated micrometer, they measure the same thing but to different accuracy.

they are different types though, if you compare two micrometers there wont be much if any difference betweem them if they have been calibrated

 

[silver surfer]

Not exactly your normal common a garden low resistance meter though is it?? This is what is commonly know as a ''Ductor'' tester that applies a high current into the test piece via current and voltage probes (4 point contact probes)!! Oh and probably costs around the 2k to 2.5k quid mark...

Did i mention, it's also a totally inappropriate bit of test kit for measuring the resistance of circuit wiring to boot.....

But never the less an option for the OP to ponder.............
Lets not make presumptions on his available budget or technical capabilities..............
That would be rude...................

 

[silver surfer]

Sure there is, ....it depends on the accuracy of the meter, generally the higher the accuracy the higher the cost!! lol!!

Agreed anywhere up to 2.5 grand

 

[davesparks]

they are different types though, if you compare two micrometers there wont be much if any difference betweem them if they have been calibrated

There could be a big difference between them! Being calibrated doesn't affect their accuracy.
One could be accurate to .01mm and one to .001mm for example.
In the same way one ohmmeter could be accurate to .01ohms and one to .001ohms.
They can all be calibrated as many times as you like but one will always be more accurate than the other.

 

[shanky887614]

There could be a big difference between them! Being calibrated doesn't affect their accuracy.
One could be accurate to .01mm and one to .001mm for example.
In the same way one ohmmeter could be accurate to .01ohms and one to .001ohms.
They can all be calibrated as many times as you like but one will always be more accurate than the other.

they have different scales so cant really compare which is more accurate.

this is on the spec sheet when buying

this is the same as you comparing a multimeter and whatever tester you use on 11kv etc

 

[davesparks]

The two ohmmeters could both have the same scales, say 0 - 10 ohms for example.

 

[Silly Sausage]

One could be accurate to .01mm and one to .001mm for example.

We're talking about Resolution there.
Instrument accuracy is a completely different bag of frogs.

 

[Dcf]

I have a megger bmm 500
passes every time on the checkbox( not calibrated as it's not my main test kit any more)
does k ohm and ohms and also tests to 10G ohm on insulation @1000v
had it 12 years
sometimes come up on ebay cheap.
modern equivelant is a MIT 420 I think.

 

[davesparks]

We're talking about Resolution there.
Instrument accuracy is a completely different bag of frogs.

Good point!

But the point that two calibrated instruments could have two different accuracies is still valid.

Let's say one ohmmeter is accurate to 0.05% and one is accurate to 0.01%
Both can be calibrated but will have different accuracies.

 

[Silly Sausage]

Don't forget to account for the 'Digit' error on bottom end readings Dave!
A lower %age accuracy meter is not necessarily better at those low low measurements.

 

[davesparks]

I never said it was, shanky stated that once calibrated all meters have the same accuracy. My point is that this is not correct.

 

[uksparks]

Just read this thread title, I mean flipping heck, why do you need it any more accurate? It's only got to be over 1M ohm strictly speaking, and we are talking of millions of ohms here, it's hardly like we are talking abouts natts whiskers. If my meter tells me a circuit is 100M or 500M I could care less, it's a zillion TOM'S higher than 1M.

 

[Engineer54]

But never the less an option for the OP to ponder.............
Lets not make presumptions on his available budget or technical capabilities..............
That would be rude...................

Yeah, ....for about a micro second!! lol!!

Nothing to do with making OTT presumptions, a typical journeyman electrician, (as well as many small electrical contractors) would not carry such test equipment. Primarily because they wouldn't ever have a need for such test kit....

So when exactly have you, or anyone else ever used a 4 terminal micro ohm Ductor tester, to test a circuits wiring?? It's a totally inappropriate tester, and not what the OP was asking about!!

 

[silver surfer]

Yeah, ....for about a micro second!! lol!!

Nothing to do with making OTT presumptions, a typical journeyman electrician, (as well as many small electrical contractors) would not carry such test equipment. Primarily because they wouldn't ever have a need for such test kit....

So when exactly have you, or anyone else ever used a 4 terminal micro ohm Ductor tester, to test a circuits wiring?? It's a totally inappropriate tester, and not what the OP was asking about!!

as recent as last week actually. Measuring r1r2 on 100 metre runs of 240mm conductors in parallel, 12 cables in total.
the instrument reading was bang on the pre-calculated values as well. Well worth the 40 quid a week hire charge.

i obviously wasn't as entirely clear on the OPs requirements as you were. Didn't realise he was a typical journeyman spark either....

 

[Engineer54]

Really, i thought it was pretty clear what the OP was asking, and it wasn't anything to do with a 4 point Ductor tester!!

So how did you link out those 240mm parallel conductors at one end then??

 

[davesparks]

By twisting then together?

 

[Engineer54]

By twisting then together?

Probably did too!! lol!!

I just can't understand why you would conduct r1 r2 testing on parallel 240mm conductors?? Calculation is more than satisfactory. I certainly wouldn't conduct such tests on what sounds like a main supply, or large sub main....

 

[silver surfer]

Probably did too!! lol!!

I just can't understand why you would conduct r1 r2 testing on parallel 240mm conductors?? Calculation is more than satisfactory. I certainly wouldn't conduct such tests on what sounds like a main supply, or large sub main....

Oh really ? Lol

calculation or presumption ? Seems more in keeping Lol

 

[Engineer54]

Oh really ? Lol

calculation or presumption ? Seems more in keeping Lol

Ha ha, ....Come on clever cloggs, tell us how you conducted these pointless r1, r2, r n tests with the DLRO 10??