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Meter Probe

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Peter Bell12/08/2019 18:57:01
275 forum posts
132 photos

I'm running short of simple meter probes, eveything I look at is either expensive rubbish or not what I want.

This is what I've previously used, plugs onto a bannana plug lead (4mm?) so I can change it for a croc clip.

Does anyone recogise them and know if anything similar is still available?

Thanks Peter

meter probes.jpg

Rob Rimmer12/08/2019 19:01:46
112 forum posts
1 photos

CPC do a selection which may be suitable - see here

Don Cox12/08/2019 19:21:14
35 forum posts

I'm pretty sure those were the ones which came with most B.T. test gear when I last worked for them, now 23 years ago. In all that time I've never been able to track down a source of supply for replacements and I too have had to buy sub standard flimsy stuff. I'll be interested to see what else comes up.

Don

Nick Clarke 312/08/2019 19:53:39
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326 forum posts
8 photos

If you are looking for ex GPO what about the Rugby Radio Rally this Sunday at Princethorpe College?

peak412/08/2019 20:31:37
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782 forum posts
67 photos

Certainly the same as Post Office Telephones/BT as they are exactly the same as the ones I use.

I've been looking for a few myself.

Bill

Peter Bell12/08/2019 21:00:11
275 forum posts
132 photos

Yes looks like they are GPO/BT and we all want some!

Think I bought a box of them at the Telford rally some time ago. Cannot find the box which would have the part no on them.

Peter

Diogenes12/08/2019 21:11:39
7 forum posts
6 photos

..this kind of thing?

https://uk.rs-online.com/web/p/multimeter-test-leads/1247406/

Robert Atkinson 212/08/2019 21:25:00
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306 forum posts
17 photos

The old BT leads were only designed for low voltage use. You should really only use leads and probes with sleeved safety plugs. Buy them from a reptutable supplier like RS Farnel, CPC or electrical factor. If you are a business or employer of any sort you must use appropriate safety leads. For domestic mains on the "user" side of the socket they should be "CAT II" at least andfor house wiring work CAT III see http://www.hse.gov.uk/pUbns/priced/gs38.pdf

Robert G8RPI.

Don Cox13/08/2019 09:42:35
35 forum posts

Over the 33 years I worked for PO/BT I had pretty much daily contact with their multi-meters, both as an exchange maintainer and as a linesman. Over that time the test gear was updated and the test leads too. One of the more annoying "improvements" was to the test leads which joined the probes, pictured above in the original posting, to the meter. Later ones of these had spring loaded insulating shrouds which covered the bare metal lead ends if they weren't plugged in. These had the very annoying effect of forcing the probes off of the end of the meter leads at the crucial moment. The need to get the probe onto a soldered tag deep inside a switch was difficult enough without the thing coming away in your hand just as you were going to look at the meter.

The latest standard test leads are next to useless in those type of circumstances, so the message must be look after any of this kit you still have, there ain't going to be anymore.

Don

Mike Poole13/08/2019 10:07:55
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2011 forum posts
46 photos

Testing has become increasingly difficult as the requirements for shrouding have become more onerous. Needle points are useful for checks on PCBs that have been lacquered, they can also be useful for piercing the insulation on cable, obviously this must only be used where the pinhole left will not compromise the safety and integrity of the installation and personnel. Sometimes you can have fond memories of slate backplanes and rigid bare interconnections, accessibility was easy but so was an accidental touch when live testing.

Mike

Neil Wyatt13/08/2019 20:57:53
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Moderator
16232 forum posts
675 photos
74 articles

Even my cheapest £5 'disposable' multimeter has shrouded plugs. Sobering that it is an order of magnitude + more accurate than my expensive old moving coil meters.

My better meter has shrouded plugs and only the very tips are bare - I find this style much easier to use TBH.

Neil

Peter Bell14/08/2019 08:24:22
275 forum posts
132 photos

Yes spring loaded shrouds were really annoying with leads popping off all the time. Also had bad experiences with lower priced meters belonging to others, the meters work fine but the leads just dont last.

Sorted for now but its opened my eyes to whats available for the future so thanks everyone.

Peter

John Haine14/08/2019 08:55:26
2571 forum posts
133 photos
Posted by Neil Wyatt on 13/08/2019 20:57:53:

Even my cheapest £5 'disposable' multimeter has shrouded plugs. Sobering that it is an order of magnitude + more accurate than my expensive old moving coil meters.

My better meter has shrouded plugs and only the very tips are bare - I find this style much easier to use TBH.

Neil

Or at least precise? wink

Robert Atkinson 214/08/2019 12:23:15
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306 forum posts
17 photos

The 4mm plugs with spring loaded sleeves are pretty useless and no longer common (or acceptable for new mains rated leads).

When teaching use of meters I had a "lesson" on digital accuracy. It involved a PP3 battery, AVO Model 8 analog meter (1%) and AVO DA116 digital meter (0.5% +1 count). Tne lesson was to measure the battery with both meters and discuss the results. The Model 8 read around 8.4V and the DA116 read 9.0V. Most students said the Model 8 was out of calibration and inaccurate (dispite having a in cal sticker) by 0.6V. A small percentage said the DA116 was faulty. - these had noticed that the PP3 was a rechargable with a nominal voltage of 8.4V. The DA116 had been deliberately adjusted to over-read. More digits does not mean more accuracy. The DA116 was only good to +_ 0.055V making the last digit virtually useless.

Robert G8RPI.

Peter Bell14/08/2019 12:36:37
275 forum posts
132 photos

All interesting stuff.

I find I quite like using my Avo 8 occasionally especially if I'm reading current, I find it far easier to follow a swaying needle rather than rolling digits and of course it doesnt power off after a few minutes.

Peter G4LSA

Neil Wyatt14/08/2019 16:13:24
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Moderator
16232 forum posts
675 photos
74 articles
Posted by John Haine on 14/08/2019 08:55:26:
Posted by Neil Wyatt on 13/08/2019 20:57:53:

Even my cheapest £5 'disposable' multimeter has shrouded plugs. Sobering that it is an order of magnitude + more accurate than my expensive old moving coil meters.

My better meter has shrouded plugs and only the very tips are bare - I find this style much easier to use TBH.

Neil

Or at least precise? wink

No, very much more accurate, at least if the agreement of multiple meters on a reading and the occasional test against an accurate reference voltage is sufficient test. Essentially, it isn't any more expensive to make them accurate to within a few tenths of a percent, so there's no incentive to make them less accurate.

Neil

Dave Halford14/08/2019 19:23:16
414 forum posts
4 photos
Posted by Don Cox on 13/08/2019 09:42:35:

Later ones of these had spring loaded insulating shrouds which covered the bare metal lead ends if they weren't plugged in. These had the very annoying effect of forcing the probes off of the end of the meter leads at the crucial moment. The need to get the probe onto a soldered tag deep inside a switch was difficult enough without the thing coming away in your hand just as you were going to look at the meter.

The latest standard test leads are next to useless in those type of circumstances, so the message must be look after any of this kit you still have, there ain't going to be anymore.

Don

Still got mine and they still push the probes off smiley

Mike Poole16/08/2019 09:44:45
avatar
2011 forum posts
46 photos

E-Z Hooks were one of my favourite small probes for bench repair work E-Z Hooks

Mike

Anthony Kendall16/08/2019 11:06:08
57 forum posts
Posted by Peter Bell on 14/08/2019 12:36:37:

All interesting stuff.I find I quite like using my Avo 8 occasionally especially if I'm reading current, I find it far easier to follow a swaying needle rather than rolling digits and of course it doesnt power off after a few minutes. Peter G4LSA

Peter - me too. I know exactly what you mean. I use digital about 95% of the time.
I find there are times when either has an advantage. Robert Atkinson's post was very interesting. The younger might be much more at home with digital, whereas the older are more at home with an Avo? I liken it to using a word processor - I can see errors much better if I print out - and I think that's an age thing!

It is amazing, though, what functionality and accuracy you can get from a 25 quid digital multimeter. Very good value, whatever leads you put on it.

Robert Atkinson 216/08/2019 11:09:45
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306 forum posts
17 photos
Posted by Neil Wyatt on 14/08/2019 16:13:24:
Posted by John Haine on 14/08/2019 08:55:26:
Posted by Neil Wyatt on 13/08/2019 20:57:53:

Even my cheapest £5 'disposable' multimeter has shrouded plugs. Sobering that it is an order of magnitude + more accurate than my expensive old moving coil meters.

My better meter has shrouded plugs and only the very tips are bare - I find this style much easier to use TBH.

Neil

Or at least precise? wink

No, very much more accurate, at least if the agreement of multiple meters on a reading and the occasional test against an accurate reference voltage is sufficient test. Essentially, it isn't any more expensive to make them accurate to within a few tenths of a percent, so there's no incentive to make them less accurate.

Neil

Hi Neil,

I doubt any cheap meter is an order of magnitude more accurate than an expensive anlogue meter. A classical analogue meter like an AVO 8 has a specificed accuracy of 1% on DC volts. Even a good 31/2 digit DMM e.g. Fluke 110 series is only specified to 0.7 percent. plus 2 counts. Any 31/2 digit meter (1999 count) has only 0.05% resolution so with the best uncertanty of 1 count even if everything else is perfect they can only make 0.1% of full scale. Accuracy for AC, current and resistance is poorer. A single point check is not confirmation of overall accuracy.
Accuracy, precision, resolution and linearity all need to be considered. A great book on the subject is "Calibration Philosophy in practice" by Fluke.
I'm a bit of a ""volt-nut" I have meters up to 81/2 digit resolution, good solid state voltage references, Kelvin-Varley dividers etc.

Robert G8RPI.

Edited By Robert Atkinson 2 on 16/08/2019 11:11:09

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