Analog vs digital micrometers

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Mr Ron
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Analog vs digital micrometers

Post by Mr Ron »

I know micrometers are the tools to go to when accurate measurements are to be made, but how does a digital micrometer compare to the analog type? Are digital readouts reliable?
Mr.Ron from South Mississippi
rustyh
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Re: Analog vs digital micrometers

Post by rustyh »

I have an iGage that seems okay so far. Got it after I found a young lad tapping in a piece of inlay with my old Starrett, which has now been "put away" out of sight. It's the problem with having tools in sliding drawer cabinets, hammers were in the drawer below... :roll:
clive
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Re: Analog vs digital micrometers

Post by clive »

Analog for me, there's less to go wrong.
Lew Hartswick
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Re: Analog vs digital micrometers

Post by Lew Hartswick »

clive wrote:Analog for me, there's less to go wrong.
:-) another one of the "KISS" examples. :-)
...lew...
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seal killer
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Re: Analog vs digital micrometers

Post by seal killer »

Mr. Ron--

I imagine a quality digital mic, like a Mitutoyo, would provide superior readings to the fourth and fifth decimal places. I would like to have one and may get a 0-1" Mitutoyo. But, for everything I do, my old 0-1" Starretts and Brown and Sharpe mics work well for me and I really enjoy using them. I have some old larger mics, as well, but I don't think they are marked with a manufacturer. (I'll look, again. I've forgotten.)

If I had had a quality digital mic several years ago, I would have never learned to read an analog mic, which would have been a loss for me.

--Bill
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Mr Ron
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Re: Analog vs digital micrometers

Post by Mr Ron »

The way I look at it, an analog mic doesn't lie. The lines line up and there is no way you can misinterpret their meaning. With a digital mic, or anything digital, you don't know if the reading is true, or did a glitch in the electronics change the numbers somehow. An example would be; not zeroing the readout before taking the measurement.
Mr.Ron from South Mississippi
morsetaper2
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Re: Analog vs digital micrometers

Post by morsetaper2 »

I imagine a quality digital mic, like a Mitutoyo, would provide superior readings to the fourth and fifth decimal places.
I prefer the analog mics.

Anybody can take a mic that measures to 4 or 5 decimal places and get a measurement. But how accurate will that measurement be? At 4 and 5 decimal places one needs to be careful of the temperature (and temperature differential) of the mic, the work, and the heat your hands may put into either.

Temperature control is really important, and if measurements are made on the pieces outside of the temperature the mics were calibrated in, then they are just approximate. And that 4 or 5th decimal place is worthless.

That piece that just came off the lathe that was warm, had a four or five digit measurement taken on it... Check it in an hour once its cooled. It will be smaller out in the 4th & 5th decimal place.
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seal killer
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Re: Analog vs digital micrometers

Post by seal killer »

morsetaper2--

His first question ". . . how does a digital micrometer compare to the analog type?" I interpreted as concerning accuracy. Do you think a Mitutoyo digital micrometer would provide the same or better accuracy than a quality analog mic?

His second question "Are digital readouts reliable?" seems to be directly applicable to your point about temperature control when considering the 4th and 5th digits to the right of the decimal point. The 5th digit is a meaningless number for what I do. The 4th digit has meaning now and then, especially when I am trying to get a good slip fit.

Like you, I prefer the analog micrometer. But, whenever I double-check it against my Fowler import, I always get the same reading to within a tenth or two, which is well within my working capability.

--Bill
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BadDog
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Re: Analog vs digital micrometers

Post by BadDog »

I love my Mit digital calipers for when they are appropriate. And I love my vernier calipers as well, though they are mostly used to quickly check material thickness and such for fabrication, or much like you would a rule. For precision and accuracy, I always use my vernier B&S mics. But for "must be better than calipers" but not sub-thou bearing fits, I love my mechanical digital Mit micrometer. Just quick and easy to read without worry about missing a mark and reading it wrong. I don't own a true digital mic.
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Mr Ron
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Re: Analog vs digital micrometers

Post by Mr Ron »

Somehow, the point I was trying to make was; ignoring temperature that can throw off readings, how reliable are the electronics vs direct reading analog devices that I see as not lying? Every time I take a digital measurement, I'm never sure the reading is correct. I will take several readings on the same piece and may get a range of readings. I end up using an analog tool to re-measure. I have to assume; since Starrett and Mitutoyo make digital instruments, they must be OK. I wish I could have confidence in digital readings and not pay $100 + for something that won't guarantee correct readings every time.
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seal killer
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Re: Analog vs digital micrometers

Post by seal killer »

Mr. Ron--

I understand your point, now. Similarly, I have lost confidence in my digital Fowler, although it has always verified my readings of the Starretts and B&Ss, at least out to three decimal places. Now that I am thinking about it, I have never used the digital mic when I needed a measurement out to four decimal places. I suppose that, unconsciously, I never turned to it for exactly the reason you stated. But, at the time I didn't have enough experience to know WHY I didn't turn to the digital mic. Now, thanks to you, I do.

--Bill
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Downwindtracker2
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Re: Analog vs digital micrometers

Post by Downwindtracker2 »

It could be an age thing. Last fall I worked a shut down at a lead smelter to pay for my tooling up. They were short of millwrights , so I came off the retirement board. One of the small crew was just off the plane from Australia, a late 20s machinist who had worked mostly tool and die. For this job, he had to buy a new set of tools as he hadn't brought his old ones over, he made point of buying expensive Mit calipers. He had great faith in them.
A man of foolish pursuits, '91 BusyBee DF1224g lathe,'01 Advance RF-45 mill/drill,'68 Delta Toolmaker surface grinder,Miller250 mig,'83 8" Baldor grinder, plus sawdustmakers
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