Different result every time

[SparkyMalone]

Hi

Has anyone considered that every time you do a continutity/earth loop test, on the same circuit you get a different result every time?

I had an end to end test on a ring circuit today and kept pressing the test button. The results jump all over the place.

How credible is any test if the result is never the same, anyone could make up the results and we wouldnt be able to prove it, and this worries me!

 

[Stspark]

Could be a number of issues, however for a basic continuity i'd say generally an issue with the test kit or operator.

Battery level, instrument accuracy (in cal), lead condition, croc clip connection, pressure of leads on cable ect.. Few of the things i'd initially check

 

[Leader]

On my tester you need to keep your finger on the test button until it has stabilised. That way I do get the same result each time.

 

[SparkyMalone]

New test kit, calibrated with fresh batteries, constant pressure applied as croc clips secured. Results kept vayring from anywhere between 1.01-1.51 ohms

 

[Risteard]

Indeed, good points by Stspark. Always worth remembering that test instruments have an inherent inaccuracy built in - for example it may be +/-10% on some ranges. We shouldn't consider them to be inherently accurate equipment, but more indicative.

 

[static zap]

Are you waiting between tests , some whack enough current about to warm things
a little , for a different reading next time !
(What gear are you using - does it need its leads zeroing .. (can hide problems!))

 

[SparkyMalone]

I use auto null - will try pressing button down for longer, but often use 'hands free' mode anyway.

I use the kewtech kt63

 

[static zap]

A known good -resistance is probably a useful starting point .
(if you do decide to use a drum of cable -it will change with temperature ! )
Check you meter is behaving it'self .

 

[stevethesparks]

Poor connections to meter/leads, do you make sure you null your equipment with the crock clips touching on both their fixed sides?
Is your equipment susceptible to interference? Have you tried isolating other circuits to prove this.

 

[Octopus]

New test kit, calibrated with fresh batteries, constant pressure applied as croc clips secured. Results kept vayring from anywhere between 1.01-1.51 ohms

Send it back for a warranty check ................ if its new kit the results you are getting are unacceptable.

When my Metrel starts doing this, I know its time to replace the leads - which is about every 15 months)