Unusual Go-No Go Tool?

My search in Cornell’s library was a little disappointing: **LINK**

https://www.cornell.edu/search/?q=micrograph+polygraph#

MichaelG.

Thanks, pgk

If my reading is correct, then Moh’s micrographic surgery simply involves the use of microscope imaging to confirm that the cancerous tissue has been fully excised .. so I don’t think this gets us any further towards understanding the device.

If I’ve missed some important point, please do let me know.

MichaelG.

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[quote]
Mohs surgery is a precise surgical technique used to treat skin cancer. During Mohs surgery, thin layers of cancer-containing skin are progressively removed and examined until only cancer-free tissue remains. Mohs surgery is also known as Mohs micrographic surgery.

Hi Michael,

I have tried "Micrographs" as a company, as 100 and 300 Micrographs being a unit of measurement. I have tried it as a "Pocket type current setting device", as well as voltage. Putting "vintage" or "antique" into the search does nothing either. The searches assume that one is looking for a device to buy or information about Micrographs, ie pictures.

A real enigma this one.

Regards

Gray,

Pondering if it's a spark voltmeter (electrostatic, not power) I looked up the formula in hope it would match Michael's graph of the instrument's scale.

The formula is:

kV = 3 * air_pressure * spark_length + ¹·³√spark_length

Although it contains an exponent, ¹·³√, I don't believe the formula curve matches the instrument.

And if it's a spark device, I agree with Michael's comment - 'seems like an accident waiting to happen.'

Possibly 'Micrograph' is a reminder, 'this tool belongs with the micrograph', and isn't the name of the tool itself or a tradename. Another meaning of micrograph is an instrument for making small engravings, though I don't see how electrostatics would play a part in that. Some sort of scale reducing Xerox machine maybe?

Dave

That was my take on it too but I did wonder whether the actual surgery was just thin skin planing or some other technique since cutting cancerous tissue always risks cells breaking off into circulation It would be possible (not sure if applicable here) to use fine wires to plane and cauterise then again the tissue cells would be too distorted to identify. There is a method of using a radio frequency cutting tool that leads to far less tissue distortion but that is bound to post date your gizmo. Quite fun to use if one got the settings right from destroying an abnormal eyelash hair follicle to slicing through an abdomen.
Link

https://www.medicalexpo.com/prod/ellman-international/product-68342-606351.html

pgk

SOD

.You're starting to sound like great grandad Q..

pgk

"A real enigma this one"

Perhaps used for pushing down the keys on a coding machine?.........

Hat, Coat etc....

Martin

Michael,

Just thinking out loud here....

...but if Micrographs isn't the maker's name then the device has no maker's info or serial number etc. which suggests that it may have been made 'in-house'. In that case a "graph" could be informal in-house jargon. For example, "100-300 micro grays per hour" is not an outlandish scale.

Keith (who knows nothing about radiation measurements, except what Google just turned up)

I have just been looking at Martin's original pictures again.

The lettering looks to have been engraved and the "C" does not look quite right to me, Suspecting it might be a badly formed "G". The wax or white paint filling may have come out of the lettering.

Doing a search for MIGROGRAPH did to my surprise show some results, but again to do with electron microscopes.

I have yet to discover what a MIGROGRAPH is other than a miss typed word, but for there to be 10 pages in the search I cannot believe that there would be many hits for a miss spelling.

Regards

Gray,

Promising:
The linked article is dated 1911 and describes a new instrument for detecting minute motions of a diaphragm with applications for physiology and physical science.
Unfortunate that the full article is members/subscription only
I know Michael found similar links but this may be one of the first...
Link

https://jamanetwork.com/journals/jama/article-abstract/438880

pgk

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Nice try, Gray … but inspection under the stereomicroscope confirms the letter to be C

MichaelG.

This one's for you, Gray

[ click ^^^ for larger image ]

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MichaelG.

I'm still thinking old magneto tester. Remove screw cap from spark plug. Insert through square hole & through the small hole. Screw cap back on the plug with H.T cable attached to it. Back off the insert to not go side. Start magneto & slowly screw the shaft in until the plug sparks. Which the H.T would at some point when the brass pointer gets close enough to let the spark jump across it.

Steve.

But the pointy thing would be aimed at the ceramic,

Hi Michael,

Having done my fair share of engraving whilst working in the Oncology Workshop, I know how easy it is to make a mistake, at least it was worth a shot.

One question, When the instrument is in the "Go" position, or Zero, do the two contacts, contact? Or is there still a gap? (Two questions really I suppose).

Regards

Gray,

Edited By Graham Meek on 24/08/2021 10:40:28

A somewhat belated ‘fact check’ …

The ‘square’ is approximately 10.3 x 10.6mm, with rounded corners

The hole is about 2.25mm diameter, and not quite central in the width of the strip

The clip [previously assumed to be a viewfinder] is bent and twisted from flat strips of brass/bronze.

Presumably fit-for-purpose … but not ‘precision’

MichaelG.

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I’m a little confused by the GO - NOT GO arrangement of this device

You will see that the line above the scale window is discontinuous … which suggests three states !

In answer to your question : There is still a small gap [a few thou’] when the scale is reading zero

[ and, just for info, the thread disengages about one turn beyond the 300 mark ]

MichaelG.

The part that confuses me is that Go/ no-go gauges are usually fixed. The idea of an adjustable go/no-go gauge kind of defeats the point....

Unless of course the difference between whatever is Go and Not Go is fixed and moves with the adjustment. In what capacity, I have no idea.

The scaling I would assume is down to the inverse square law.

Edited By Jon Lawes on 24/08/2021 13:40:01

Hi Michael,

I noted the gap in that line. It reminded me of the Zero line on a micrometer barrel at first, but then why the gap. As there is no room on the adjuster for a second scale I ruled that out.

What does not settle with me and why I asked the question.

If this tool was for testing spark strength then the "Go" condition would pass a fairly weak spark. Whereas the "Not Go" would be failing one hell of a spark. So the scale to me does not make sense for that application.

It may well be that the sweet spot for setting what ever this tool was setting is in the 0-50 range, there being more graduations, the rest of the scale being arbitrary.

We had settings on the Varian Linear accelerators that were in the preferred range, although these settings were well within the upper and lower accepted values, and in many cases not in the middle.

Regards

Gray,

Yes of course Gray. You are right the wording would be opposite, if for a spark. Doh.

Steve.