Test Leads ?

[Evans Electric]

Anyone know why test leads appear have a resistance not in proportion with their length ?

My testers are not the latest and are 3 seperates , which is a pain.          Anyway with my Martindale ohms , megger & volts the null option packed up so I have to deduct 2.41 ohms from the readings .  

Is that the leads , which I could change, or is that the internal resistance of the meter?

 

[Andy™]

put a very short bit of wire between the terminals on the meter and see what you get

2.41 is very high... iirc its around 0.07-8 on mine

 

[Sidewinder]

Deke,

Do you have any other leads you can use?

Can you check the resistance of each lead, where you connect it across the terms on the meter to see if it is one lead or both?

It could be the connections in the meter?
Does it have an internal fuse?

Could the fuse holder have weakened over time?

 

[Evans Electric]

I'll check those things tomorrow , especially the short bit of wire.    They've all just been re-calibrated but I don't suppose they check them over for anything else.    Pretty sure theres a fuse carrier in the base .  I only have one set of leads of that type I think.

Canoey ,  "  I have so much money"    Have you seen my van ?     I don't really want to be replacing instruments now , they've done 20 years service ,another couple won't hurt them !

 

[Sharpend]

Deke - You have so much money - Stick it on ebay for a fiver - Buy a new one from MM

See my Sig for MM details  :innocent

Are you on a commission!!!!!!

 

[Evans Electric]

He must have shares .

 

[Evans Electric]

Powerkut ...they have a small branch  near me .   1/2 mile away.

Why,   do you think they should check everything ?     On saying that , they should have picked up on the null button not working I guess . 

 

[Evans Electric]

Another question while on the subject ..........why are replacement leads so expensive FFS?  

I know ...I know...I know    but what would the postage be there and back and would they survive the postal system  I ask myself ?

I did consider it .......they charged £ 93.60   with the VAT    for the 3 testers .

Logging off

I'm back later .

 

[Sidewinder]

I did consider it .......they charged £ 93.60   with the VAT    for the 3 testers .

OUCH!

 

[kerching]

Another question while on the subject ..........why are replacement leads so expensive FFS?  

I know ...I know...I know    but what would the postage be there and back and would they survive the postal system  I ask myself ?

I did consider it .......they charged £ 93.60   with the VAT    for the 3 testers .

Logging off

I'm back later .

Did that include the tubes of Anusol and Bottom Balm?

Cost me about that for an MFT, Torque calibration Tester ( they had not seen one before either ) and something else, cannot remember what....summat electrical

Just promoting

 

[Evans Electric]

Well  £26.00  for each instrument   ( before VAT ) 

What are folks paying for re-calbs I ask?  Is it worth paying the postage I ask? 

Much the same price at a Denmans Calibration Day .

 

[Evans Electric]

Had a close look at the tester earlier today , with a short across the output terminals the meter  seems to have a resistance of 1 hms .

The red lead causes the reading to fluctuate and clearly has a problem , I found another set which have a resistance of 3 hms  

Picture is the original leads which eventually settle on 2.2 hms

 

[SPECIAL LOCATION]

Original leads??

surely the crop clips will be introducing all sorts of dodgy resistances by now???

Are there no equivalent leads here that will fit your meter..?

http://isswww.co.uk/Test-Leads/

I am sure MM could do you a decent price....

Guinness

 

[Steve3948]

True dat

 

[Sharpend]

I'm glad you put an explanation there paddler, I was worried deke was going to turn it by 180, then complain he couldn't read the screen!!!!!

 

[kerching]

Try connecting the croc clips together with a short bit of clean copper (6mm?)

(Saves having to do it on your head.....180 degrees.....turned upside down.....never mind)

Also just saying

 

[Evans Electric]

I'm not sure about this advice ....I managed to hang from the roof purlin by hooking my feet over it , above the bench and reconnect the crocs in the approved manner    ( I hadn't noticed I did that )  

  I then reversed the crocs and got the same result ,  realised I had re-connected them in the same but opposite manner  so then hit upon the brilliant idea of standing a mirror on the bench and , looking through into it , reversed the leads again which put them back as they were .  I then became confused when reading the  eladnitraM  so picked up an old wing mirror and so by looking at the reflection of the wing mirror in the larger mirror I finally connected the leads in the approved manner  but couldn't read the read out  because moving the retem to the tfel causes it to move to the thgir where it fell off the bench   

It was about this time that my feet slipped out of my work boots , fell onto the  bench , bounced off onto the front of my van and from there onto the floor ,   I then stood up gingerly and my Totector work boots dropped off the purlin hitting me on the head .

I should be home for Christmas.