Unusual Go-No Go Tool?

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O.K. Steve … let’s just say your comment touched a raw nerve.

MichaelG.

Michael i think you underestimate yourself. I have the impression that you are highly regarded on this forum. At least i look up to you. I did the item to death & came up with nothing. I really do hope you find what it is.

My Uncle worked at a nuclear plant in Cumbria some years ago & had a similar device , which he always kept in his top pocket. It was to make sure that any area he entered was not radio-active. I followed that path & found nothing. Hope you do better.

Steve.

That would be a quartz fibre dosimetry, getting to be old hat when I was regularly visiting Sellafield, and that's a fair few years back. It's all done electronically now. I only had one scary moment, alarm went off continuous rather than the occasional beep. Turned out the battery was nearly flat. I don't glow in the dark

Edited By duncan webster on 15/08/2021 00:59:08

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Thanks for the positive thought, Steve … but the fact is: I have, in the past, suffered some extremely hurtful personal comments from individuals on this forum.

Let’s just leave it at that, please.

MichaelG.

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That’s not a device with which I am familiar … but curiosity led me to this : **LINK**

https://www.radiation-dosimetry.org/what-is-quartz-fiber-dosimeter-self-indicating-pocket-dosimeters-definition/

MichaelG.

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Edit: __ and this [non pocket-sized] variation on the theme:

http://waywiser.fas.harvard.edu/objects/14362/quartz-fiber-electroscope-dosimeter

Edited By Michael Gilligan on 15/08/2021 06:23:15

That's it. You looked down one end, which seemed to have a hair or something fine , which i believed would move across as the Rad got higher.

Steve.

The strange device arrived in today’s post, Martin

Many Thanks

There will now be a [probably long] pause, whilst I try to decipher its function.

MichaelG.

Some minor discoveries already [but no real progress towards identification] …

A) The body and the screw are both made primarily of Ebonite, or similar … suggesting, but not guaranteeing, that they are acting as electrical insulators.

B) The screw can be removed completely, and it carries a brass rod which is tapered to a conical point.

C) There is an insert within the tube, visible through the ‘windows’ … and adjusting the screw changes the gap between this and the cone. This has the ‘feel’ of being a spark-gap, but there doesn’t appear to be a connection to either pole.

D) The pocket clip is plated steel and presumably a ‘bought-in’ commercial item; and it carries the number 5 and the words MADE IN ENGLAND, stamped on the inside of the straight clip.

E) The other metal parts all appear to be brass.

F) The gap in the engraved line above the scale is clearly ‘real’ not just missing paint.

Pictures anon

MichaelG.

Michael,

I wish you well with your detective work on the mystery item, one thing that caught my attention is the word Micrographs on the tool body and wondered if that has any bearing on the tool use.

**LINK**

MichaelR

Thanks, Michael

As an amateur microscopist ... the word Micrographs was the first thing I commented upon, when Martin posted the question.

I have never seen it used as a unit of measure; which is why I thought it might be the Manufacturer's name [or perhaps the name of a company's department.

If you find anywhere that it is used as a unit, then I would be most grateful

MichaelG.

Some photos to illustrate last night's observations:

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The final one of these shows the conical brass point in situ

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MichaelG.

I have re-formed the peep sight into something approximating its [presumed] original shape, and it now aligns as I would expect.

I have also removed the pocket-clip and the ‘transparent’ plastic sleeve.

Doing this has revealed a spring strip which contacts the brass rod [presumably this makes electrical contact rather than just providing friction : but I’m not yet sure] … There is evidence of this rubbing, in the first photo.

I have not yet been able to separate the brass portion from the main tube … and am wary of applying much force, in case there are other surprises lying in wait.

Time to stop for a while and do some thinking/searching.

… any new ideas as to what it’s for ?

MichaelG.

It's got my mental muscles flexing (both of them!).

I wonder if its something to do with lighting, like setting filaments or gaps between electrodes in an arc lamp?

Spark plug gap setting tool for some unusual plugs? (I'm aware you mentioned this earlier)

I'm thinking a variation on the theme of a gunson device, the window allowing you to see the spark. It would explain why so much of it is of an insulating material.

Just complete stabs in the dark, no background knowledge

Edited By Jon Lawes on 19/08/2021 18:51:39

I notice the clip mounts on a brass (or similar) part, does that mean the clip is a part of the circuit being tested?

Thanks for the thoughts, Jon

The word MICROGRAPHS is really niggling me … but I was just thinking about early electron microscopes and the ridiculously high voltages associated with them.

So far as I can see at the moment, there are no ‘terminals’ connecting to the outside world … although, as yet, I don’t know what might be inside that brass ring.

I’m thinking electrostatics … but that seems like an accident waiting to happen.

MichaelG.

I'm not clever enough to do things without google so I did pound companies house etc on the off chance it referred to something other than microscopic photography or similar, as mentioned. A few names bubbled up from the archives but nothing relevant.

I ran it through an image search as well, nothing similar came up. A real puzzler!

Good to have you on board, Jon

MichaelG.

It’s certainly not one of these … but I think we may be heading in the right direction.

**LINK**

https://www.worthpoint.com/worthopedia/vintage-minerallac-pocket-type-1920532728

MichaelG.

http://www.antique-microscopes.com/chemistry/Leitz_hand_spectroscope.htm

The clamp on the end keeps bringing me back to spectroscopes (or even, as a tangent, a method of calibrating them with the go/no-go element), but without an optical element that's rather a bum steer. Maybe it will jog someones memory.

I did see a photo of something similar where a square clamp at the bottom held a very old looking square prism (almost crystaline rather than optical), but I can't find it again now.

My ‘working assumption’ has been that the bent-strip device is a crude version of a viewfinder:

**LINK**

https://kamerastore.com/product/linhof-peep-sight-wire-frame-finder-en/

… and it would certainly function as such.

BUT … as I have no idea how one might use a viewfinder on this gadget, I am happy to entertain the suggestion that it could be a clip to hold a sample.

MichaelG.