R1+R2 of zero zilch nothing?......

[Baddegg]

Testing R1/R2 on 10mm/4mm T&E cable and the reading is 0.00? Never had this before, can I record 0 on the cert?

 

[MDJ]

Sorry Pete and mdj,on my testers you just select continuity if there is a scale selection I’m not aware of it?...

Fair comment fella, some testers have different scales, and if your on the wrong one a zero showing isn't unusual hence mine and Petes question.

 

[Pete999]

Sorry Pete and mdj,on my testers you just select continuity if there is a scale selection I’m not aware of it?...

So you have no LOW resistance scale on your MFT?

 

[Strima]

Resistance of copper per metre(mohms/M) appendix I of OSG:

10mm=1.83
4mm=4.61

1.83+4.61=6.44

6.44*8=51.52

51.52/1000=0.05 ohms.

 

[MDJ]

Sorry Pete and mdj,on my testers you just select continuity if there is a scale selection I’m not aware of it?...

Fair comment fella, some testers have different scales, and if your on the wrong one a zero showing isn't unusaul hence mine and Petes question.

Resistance of copper per metre(mohms/M) appendix I of OSG:

10mm=1.83
4mm=4.61

1.83+4.61=6.44

6.44*8=51.52

51.52/1000=0.05 ohms.

Show off

 

[Pete999]

Sorry Pete and mdj,on my testers you just select continuity if there is a scale selection I’m not aware of it?...

So you have no LOW resistance scale on your MFT?

What scale have you set on your MFT?

 

[Deleted member 26818]

Make sure, you join the line and CPC together at the other end from where you are testing.

 

[Octopus]

I would suggest you also try R1 + Rn

 

[Pete999]

Fair comment fella, some testers have different scales, and if your on the wrong one a zero showing isn't unusual hence mine and Petes question.

 

[Fitzy]

Have you got any old or new lengths of cable you can test your MFT with?

Do you also have a ‘Calibration Card or a calibration box’?

We used the Kewtech KT63 MFT in training and they’re
auto-ranging.

 

[Andrew Marshall]

Need a ohmmeter / multimeter with a resolution of 3 digits, ie 3 decimal places. Most multifunction testers are only 2 places

 

[Baddegg]

Thanks Archy

 

[Baddegg]

Thanks to all who replied as always loads of good advice,

 

[westward10]

What you could do it add a known higher resistance in the circuit as your circuit resistance is so low. Take a length of 1.0 singles which will add significant resistance and measure this resistance, then incorporate this into the circuit and remeasure. If you deduct the resistance of the first reading from the second you may get a result for the cable.

 

[Baddegg]

Resistance of copper per metre(mohms/M) appendix I of OSG:

10mm=1.83
4mm=4.61

1.83+4.61=6.44

6.44*8=51.52

51.52/1000=0.05 ohms.

Thanks strima, that calculation with Archie’s advice would account for the zero reading,
I am going to run some test tests tomorrow to put my mind at ease that the testers are working correctly, I’ll cut cable to exact lengths and then compare to osg/byb

 

[Octopus]

Thanks to all who replied as always loads of good advice,

Good man ............... no arsey responses , and feedback too

Seriously, this is how the forum should be - competent sparks, helping sparks

And if you do cut lengths, don't do them too short ...........