Michael Gilligan | 20/08/2021 14:17:55 |
![]() 23121 forum posts 1360 photos | Posted by Michael Gilligan on 20/08/2021 06:52:29:
[…] 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. . Having [or so I thought] successfully re-formed the strip slightly, to make the ‘sight’ work properly; it now appears that I have actually deformed it from the shape required for it to function as a pair of electrical contacts for some [as yet unidentified] component under test. I probed it with the multimeter and discovered that:
There is surface corrosion on the brass rod, but I am sure that it would be in good electrical contact if it was clean. So … the moral of the story to date is : Don’t assume that because it looks like something you know, that’s what it actually is ! MichaelG. . P.S. __ I remain utterly bewildered by the use of the word MICROGRAPHS, and have no idea what the thing tests … but it’s keeping me amused |
Steviegtr | 20/08/2021 14:37:15 |
![]() 2668 forum posts 352 photos | Does either of the 2 fingers or jaws move . I was thinking a part missing that when the bottom was screwed up it closed the jaws. Giving an exact size for an object. If under or say oversize. The marker line would show not go. Steve. |
SillyOldDuffer | 20/08/2021 14:45:53 |
10668 forum posts 2415 photos | How about a Disappearing Filament Pyrometer? The peephole and square holder takes a plug-in battery, filament, on/off switch and lens module. Does turning the base knob vary a resistance inside the handle? If so, the temperature of the filament could be altered to determine if furnace is close to correct operating temperature. I agree 'Micrographs' defies logic! Dave |
Michael Gilligan | 20/08/2021 15:38:02 |
![]() 23121 forum posts 1360 photos | Posted by Steviegtr on 20/08/2021 14:37:15:
Does either of the 2 fingers or jaws move . I was thinking a part missing that when the bottom was screwed up it closed the jaws. Giving an exact size for an object. If under or say oversize. The marker line would show not go. Steve. . Sorry but No, Steve … no movement except for them being springy … But they are each electrically connected to one of the contacts inside. All that the screw does is move the pointed brass rod [and the indicator line], so changing the size of the ‘spark gap’ The gadget appears to have no other electrical connection with the outside world … so could it perhaps be that the thing being tested is a source of energy Keep the ideas coming, please … MichaelG. |
Michael Gilligan | 20/08/2021 16:01:13 |
![]() 23121 forum posts 1360 photos | Posted by SillyOldDuffer on 20/08/2021 14:45:53:
. Does turning the base knob vary a resistance inside the handle? . No, Dave … it just moves the pointed brass rod and the indicator line Here, for convenience, is a crop from the photo that I posted before: . MichaelG. |
Graham Meek | 21/08/2021 11:14:40 |
714 forum posts 414 photos | Hi Michael, Is the the staining on the brass point similar to the powder from an arc strike? The reason I ask is that this unit clearly clips onto something with the square portion, and the hole in the other contact rest on another exposed contact area. Both these parts appear to be insulated from each other. In the view finder there appears to be a small "hair pin" electrode just beneath the clip. My reasoning is the brass point is wound in until the current jumps the gap, viewed through the view finder. The position of the red line shows if the device is set correctly. The problem is I don't know what would warrant such a tool in the electrical field. It might well be something to do with power generation. Or possibly capacitor storage capacity. Regards Gray, |
Michael Gilligan | 21/08/2021 12:05:24 |
![]() 23121 forum posts 1360 photos | Many thanks for the input, Gray Yes, the staining does have that general appearance … I am hoping to take some detail photos later today. MichaelG. |
Michael Gilligan | 21/08/2021 17:44:31 |
![]() 23121 forum posts 1360 photos | As promised : . . . . MichaelG. |
Martin King 2 | 21/08/2021 18:29:20 |
![]() 1129 forum posts 1 photos | Michael, If the grubby window part will clean up it will transform the item visually! Just wondering if there are is any small melted pitting on the inside which would support the arc idea? ie sparks? Martin (who had no idea that this thread would run on so!) Excellent detailed work. Martin |
Martin King 2 | 21/08/2021 18:30:20 |
![]() 1129 forum posts 1 photos | BTW is that a helix on the parallel brass part of the point? Martin |
pgk pgk | 21/08/2021 18:45:54 |
2661 forum posts 294 photos | If you don't like silly stories then don't read this. pgk |
Michael Gilligan | 21/08/2021 19:18:09 |
![]() 23121 forum posts 1360 photos | Posted by Martin King 2 on 21/08/2021 18:30:20:
BTW is that a helix on the parallel brass part of the point? Martin . It’s a scuff mark from the ‘wiper’ contact … pitch matches the screw thread. MichaelG. |
Michael Gilligan | 21/08/2021 19:31:48 |
![]() 23121 forum posts 1360 photos | Posted by Martin King 2 on 21/08/2021 18:29:20:
[…] Just wondering if there are is any small melted pitting on the inside which would support the arc idea? ie sparks? […] . I need to investigate this very carefully … not sure how fragile that plastic might be. As you can see; the heavy marks are on the area where the plastic sleeve is contacting the ebonite body. It will be tricky to look at the interior surface of the ‘window’ areas, but I’ll give it a go. MichaelG. |
Robert Atkinson 2 | 21/08/2021 21:44:03 |
![]() 1891 forum posts 37 photos | It is almost certainly a breakdown voltage tester. A lower voltage version of this: www.lasertools.co.uk/Product/5655/Adjustable-Spark-Tester But I can't figure out what it was connected to or the scale units. Robert G8RPI |
Robert Atkinson 2 | 21/08/2021 22:11:13 |
![]() 1891 forum posts 37 photos | Thinking some more I came to magneto tester, possibly on the primary circuit. I then found this webpage: My only other thought was testing the early medical type shock machines. That might explain the odd measurement units. Robert G8RPI.
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Michael Gilligan | 22/08/2021 07:48:57 |
![]() 23121 forum posts 1360 photos | Posted by Robert Atkinson 2 on 21/08/2021 22:11:13:
Thinking some more I came to magneto tester, possibly on the primary circuit. I then found this webpage: My only other thought was testing the early medical type shock machines. That might explain the odd measurement units. Robert G8RPI.
. Thanks, Robert … I think revelation might eventually come if we can ever find any reference to MICROGRAPHS as a unit of measurement. I know what micrographs are ; and to date, I have failed to find any other use of the word. MichaelG. |
Jon Lawes | 22/08/2021 22:25:33 |
![]() 1078 forum posts | I tried to dive in deeper to the use of the word Micrograph, and even the earliest use of the term says they are to do with Photographs taken through a microscope or by similar techniques. But in the earliest editions of Merriam Webster it also lists this version which I was unaware of: "an instrument for measuring minute movements by magnifying and recording photographically the corresponding vibrations of a diaphragm moving in unison with the original object"
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Michael Gilligan | 22/08/2021 22:36:12 |
![]() 23121 forum posts 1360 photos | That’s further away from the standard definition than I have ever seen, Jon … you may be onto something [‘though I’m not exactly sure what] MichaelG. . A good working definition for modern usage is that a micrograph is a representation of a microscopical view. We then have a sub-set called photomicrographs, where the medium is photographic. |
Michael Gilligan | 23/08/2021 07:31:06 |
![]() 23121 forum posts 1360 photos | … and on this page, Jon’s new-found definition gets top-billing : **LINK** https://medicine.en-academic.com/32911/micrograph I need to find some details of these instruments MichaelG. . and … as if by magic: Nineteen pages from 1911 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2124883/ I now need some coffee ! Edited By Michael Gilligan on 23/08/2021 07:42:51 |
pgk pgk | 23/08/2021 07:59:30 |
2661 forum posts 294 photos | Another Link for you https://www.mayoclinic.org/tests-procedures/mohs-surgery/about/pac-20385222
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