Results 1 to 20 of 46
11-20-2008, 08:41 AM #1
How big is a Micron? - Printable sheet
This should print out to scale on 8x11 paper. (Hopefully)
Just something to hang on the wall to give an idea of relative size.
11-20-2008, 10:19 AM #2
Makes me glad my tools don't measure to that, or someone would ask for it
11-20-2008, 10:54 AM #3
Hey! I did one of them a while back and it's still on my wall.. puts designers in their place when they say "what you mean you can't hold +/- 0.001mm (a micron)
PDF format attached.
11-20-2008, 12:52 PM #4
Can someone convert that to PDF?
I kant git it to scale out on the paper - can you?
First print got aboot 2/3 of it on the paper.
Next time I "scaled to fit" and I got a little tiny deal up in the corner.
Last time I went to 50% and it was a tiny little dealie up in the corner again.
Either way it's a good reference - even if I doo hafta open it up on the monitor rather than print it out...
Think Snow Eh!
11-20-2008, 01:57 PM #5
I converted it and it works, where do send the file to Ox? (about 650K)
11-20-2008, 02:51 PM #6
Thanks, just what I need for some of the muppets that come in my shop.
11-20-2008, 03:44 PM #7
That's been hanging on my wall at work for 8 years or so. I just scanned it to 8x11 and converted it to jpg from *tif. I hoped it would work.
Does give a realistic idea of how *nothing* a micron really is.
BTW, if anyone doesn't have it, Irfanview is an *excellent* [FREE] image viewer and will open about anything and allow you to manipulate it.
11-20-2008, 03:51 PM #8
11-20-2008, 10:48 PM #9
11-20-2008, 11:17 PM #10
To print it I
1 Right Click and "save image as"
2 open picture with some sort of picture viewer (from where you saved it)
3 print from picture viewer.
11-20-2008, 11:33 PM #11
11-21-2008, 12:21 AM #12
How big is a micron in human units? 40 millionths of an inch or thereabouts. 0.00003937" to be more precise.
Thing is, the scale of any unit is at it is. To marvel at the hugeness or teensiness of everyday things isn't too profitable in terms of coping.
That doesn't mean one should disregard wonder itself. Many times I've been out on a glacier for example looking down a crevass that a whole big high school building could fall into without a trace yet the glacier itself went on for miles and was moving imperceptably down valley while above it loomed the mountain dwarfed in turn by the range in which it lie. There is ample wonder in babies and how they grow. How government works as well as it does despite the people who run it. All these are wonders to behold but wonder, awe, etc should be held distinct from a rational appreciation of reality.
A micron is a unit of linear measure. We have too many units. I have a Glover Pocket Reference. In the back is many pages in small type of unit conversions. Must be thousands of them. Why do we have so many? I don't know but that's the marvel for me. Why do we tolerate this babble of naming obscure units after heroes of science when a more descriptive term like kilogram meter (to pick an obvious one) would be far more useful to someone refforming calculatiosn far from a reference book. Why is there an Orstad? An Erg? They might be heroes but naming a unit after them confuses the reader and sends him in search of a definition. I hate to send my readers running. Build the guy a statue but leave his name off all units that are not basic.
I work to microns all the time - a thousandth of an inch happens to be 25.4 microns so no biggie.
Visceral understanding of units is a different matter. You have to live and breathe them for a time if you are to look at a school bus and estimate its dimensions in meters or feet (depending on the units you didn't grow up on.) But that's a different story.
That said, somewhere I have a chart showing various small items: (bugs, mites, blood cells, bacteria of various kinds, viruses, smoke particles, molecules, atoms etc) on a logrithmic scale. Interesting and it gives you perspective - perspective: another aspect of visceral understanding.
Did I make any sense? I hope not. I'm just ranting.
11-21-2008, 01:58 AM #13
And as tiny as atoms are, the size of the nucleus in relation to the orbits of the electrons is the equivalent of a marble in an auditorium. What about the sun in relation to the solar system? Or the distance to the nearest star. It'd take like 2700 years to get there if you could travel at a million miles an hour. And that's just nothing compared to the distance to the nearest galaxy.
11-21-2008, 02:23 AM #14
Hey, Tony, thanks. I've been doing things give or take a hair all along. Now I can say +/- 0.0035 !
11-21-2008, 08:21 AM #15
11-21-2008, 10:21 AM #16
Relationships of relative size are a funny thing to the human. We work in microns for most everything we do. A micron is a very tiny amount, but with the gauging we have to reliably and repeatably measure it with it actually "looks to the human" like a lot of distance.
You put an LVDT on say a Trendsetter, set the scale for 0.2 microns, and it takes 5 marks (LEDs) on the column to equal a micron. This is about a half an inch physical distance on the scale. Makes a micron look like a 40 ft diameter bullseye for your AR at 50 yards.
The micron didn't get any bigger, but the relative size to the human eye and perception did.
And when you have machines and processes that are repeatable enough to hold a couple tenths of a micron, and gauging to measure it, it really becomes no bigger of a deal than holding +/-0.1". You don't even realize this transition of the human perception has taken place.
The most difficult part, and where reality steps in and slaps you back to the real size of a micron, is when you get the call "This machine is varying around all over the place".
In reality, it's varying 2 to 3 microns, which is really nothing in the larger sense of the world, but to a machine that normally holds 0.2 to 0.3 microns it is a 10x increase in variability. The huge problem, is trying to identify *what* is causing the variability, because at that small of a scale, it could literally be *anything* in the machine, it's environment, or the workpiece.
11-21-2008, 10:57 AM #17
I work to micron limits every day in the QC lab of a large Japanese owned automotive OEM brake supplier. The majority of the shop floor operators have no clue as to what the unit size really means and that works to the advantage of the entire company. If you told a machine line lead that he had to stop production because one of his dimensions was out of spec by .001" you'd have a fight on your hands. If you tell him it's out by 30 microns you have his undivided attention. -Mike
Tonytn36 liked this post
11-21-2008, 11:27 AM #18
11-21-2008, 11:32 AM #19
A real conversation between me and the Departmental Head (who knew bugger all about engineering, but lots about paperwork, conferences and "power naps").
Him> How come you're out by a micron on this batch?
Me> It was particularly humid that day.
Him> Eh? how would that matter?
Me> Well, the machine is controlled by laser interferometers operating at 633nm, yes?
Him> Yes, I remember seeing that in my sales brochure.
Me> And we know that the wavelenth of light is dependent on the density of the medium it's going through? yes?
Him> errrr.... ok, if you say so.
Me> Well, if the air is humid, it's more dense and so the wavelength of the laser is not exactly 633nm.
Him> *looks lost but nods wisely*
Me> So, the machine thinks it's somewhere other than where it actualy is.
Him> *crinkes forhead and rubs temples with thumb and forefinger*
Me> Added to which the temperature in the lab was 4 deg C higher than normal due to the aircon going down... You DID say "carry on anyway"... see in my lab book just here?
Him> *mumbles and shuffles feet*
Me> Look, shall I make it simple?
Him> Ah, yes.. indeed, please.
Me> Ye cannae change the laws of physics Captain. It's the Dilithium crystals. The engines cannae take it.
Him> Well, take more care of that machine- it did cost a lot you know. *wanders off with a nervous twitch now and again*
True, well almost
11-21-2008, 11:50 AM #20