Tong test

[apprentice87]

Hi All,

I bought myself an ancient Crompton "tong test" set from ebay. I wanted the thing, as it measures DC as well as AC, and so i can use it to check the output from welding sets.

I was interested to see that there is a number stamped on the "tool" and then the same number on all the meter bits.

Does this mean that they are all calibrated to the individual "tool" and that if i used the meter part from another set that it would be incorrect??

Anyone got the makers instructions?? it might say in there..

john..

View attachment 8969

 

[Tony S]

They were made as matched sets. At the foundry we had three sets made by Ferranti,  somehow the meter heads got jumbled together.

Be very careful how you use them, the tongues aren’t insulated.

http://www.electrokinetica.org/d1/3/index.php

 

[Geoff1946]

That's an impressive set. Do you know its age? I would certainly expect the calibration to be done as  paired assemblies of clamp + meter.  

 

[Evans Electric]

Yes  the dial head , I'd say,  is made to work with the laminated jaws  and was supposed to be used as a set.

I remember those sets  well.     I bet they cost a fortune back then  too.

I have one we usually keep in the office ,£80  and a cheapo Silverline  at about £15    on the van ,  the cheapo works just as good as the other after  20 yrs  rattling round the van .        

 

[apprentice87]

I will try not to electrocute myself!!!

I have no idea at all as to how old the set is, wish i knew.. It looks lovely stuff, better than the modern things?? I gave £50 for it...

Any idea as to age??

john..

 

[kerching]

I  think 1950s

 

[Sidewinder]

A marvellous piece of kit john, but, please be careful with it, as has been said.

For just over £82 inc vat without any forum discount, you can get a 400A ac/dc clamp meter from our sponsors.

It's a known brand too.

 

[apprentice87]

Hi Paul,

I never knew that, i thought that DC clamp meters were fortunes!!

Anyway, the reason i bought the tong test set, was specifically to measure the output of welding sets i have.

For this, i wanted a meter with a proper dial with a pointer, as then you can get a steady "average" [i suppose you could call it] reading, without the display changing all the time because it cannot keep up!!

I will not be using it for anything else as i could do without being killed!!

john

 

[Geoff1946]

Just out of interest, what sort of welders are you dealing with? I've only encountered AC ones.

 

[apprentice87]

Hi Geoff,

At one time, with very few exceptions, all welders were AC. There were a few DC output sets, which consisted of a motor driving a dynamo..

MIG welding was invented, and you had to have a DC output for that, so you could have a thing powered with a transformer with a big rectifier..

Same goes for TIG, unless that is, you wanted to weld aluminium, when you actually wanted AC, plus "high frequency" [Think 50V 50 Hz sine wave, but with 10kV at very high frequency, superimposed on top of it.]

You could by then, get MMA sets [stick welding] that did both AC and DC, and TIG as well, but they were huge things..

Later on though, from about the mid 1990's i suppose, you could buy lots of DC output sets, and they were portable too [only just though!!] but they were very very expensive, the like of things such as the Miller Maxstar or Lincoln Invertec.

Now though, there are loads of small portable DC output sets..

Which sort do you want?? The AC ones are more reliable and no, or very little, "arc blow" The DC ones are more portable as lighter and smaller, arc striking and stability is better, but you can often have severe arc blow..

I have loads of welders but my favorites are, from a welding point of view, for AC, my air cooled AGA TWN 330 [same as a murex transarc AC330] This is the best all round welder ever made, and for DC, my Hobart Betawave 320..

john

 

[Geoff1946]

Thanks for the comprehensive answer John. I'm always happy to learn new stuff. I only do a little welding as part of my retirement hobby of making/fixing. I learned to weld after being given a couple of broken machines and fixing them.