What's new
What's new

Early electronic metrology tools


Aug 20, 2023
I see plenty of known history of micrometers, calipers, indicators, and other tools. Yet when I try to start piecing together the early development of digital tools, there is very little. Any company history seems to treat their options as having just popped into existence one day and really the only innovation was when they invented the first blue heat shield for a digital micrometer. So, what really is the history of digital tools? I've seen height gauges with nixie displays and zero information, mentions of supposed digital calipers and micrometers in the 70's. Indicators seems to be completely lacking, and I can find patents for depth mics only from the 70's-80's era.
First posters... It's an interesting subject, there has never been a time in the world where more knowledge was easier to access with so little effort. Research isn't just asking other people to go through the effort of documenting things for you. Google "history of electric metrology" and work your way from there. Come back a write a detailed report and contribute knowledge instead of expecting others to do it for you.
First posters... It's an interesting subject, there has never been a time in the world where more knowledge was easier to access with so little effort. Research isn't just asking other people to go through the effort of documenting things for you. Google "history of electric metrology" and work your way from there. Come back a write a detailed report and contribute knowledge instead of expecting others to do it for you.
That is what I have been working on. The issue is, something being in a patent doesn't mean it got made, and information is very limited.
The oldest I can find is a xerox patent US3453752A for a comparison device that modifies a vernier micrometer with an external counter. However that just seems to compare the operator to what the electronics measure which the purpose of comparing the two is unknown. It might make sense for a training tool, possibly.
After that there are patents for the spindle head using a rotary encoder and A-B quadrature counting from many places.
1971 brings the next major portable one I find with a Japanese patent for a digital mechanical micrometer, which seems already well into the life of that style of micrometer.
The next major one I found was the 1976 digital unit from quality measurement systems, which seems to have a lot in common with the slightly later moore and wright. Glass scale and reader head vs glass scale using moire fringe counting and a constant force spring instead of a cool spring. But the moore and wright one dates to 1977, and two very similar devices springing up a year apart seems like there must be more to it. Just because I don't find a patent that is obviously a precursor to those both doesn't mean someone might not recall having used one, after all.

It's not that I have not been doing research, it's that sometimes just seeing it in a museum or a patent drawing is only half the tale, especially if nobody ever saw it or remains who knows why something was done.
So what is it you want from us? Anecdotes of the first electronic tools we used? Random stories by a few guys bored enough to humor you are no more reliable than the vague claims made by manufacturers. I've seen some pretty primitive stuff on the second hand market, but good luck dating things like that without buying them and maybe getting a date code off an IC. If you have questions, define them clearly, but don't ask people questions you can answer for yourself. Searching patents isn't exhaustive by any means, libraries provide much more value than people think.

The top Google hit for "History of Electrical Measuring Instruments" resulted in an interesting paper from the Society of Historical Metrology here in Tokyo Japan, that seems pretty relevant to your interests as electrical measurement and electrical metrology are tightly linked. Some cursory glances show an extensive amount of resources spawning from that initial search. But again, I don't know why I'm Googling for you, we all have access to the same information pool... your posts are an opaque mix of 'Hey everyone, I'm interested in this esoteric thing!' crowing and complaints that knowledge isn't immediately accessible to you. I don't mean to sound harsh, but you are coming off as a little entitled and Gen X which is raising my hackles. Information wasn't always this easy to obtain, so these complaints are grating, some knowledge is hard to obtain, it's not all on YouTube. Take this as a challenge and an opportunity to learn how to research obscure subjects.

I will throw you one more bone though:

Spend some time walking these virtual aisles and you'll come out having learned something new I'm sure.
  • Like
Reactions: ???
You need to get down in the weeds to find the info. The periodicals that electronic engineering types read and contributed to are a good source for this type of info. You will probably need to learn Japanese, Korean, Dutch and German possibly some Russian to understand most of it so good luck.
Yeah, I'm expecting to have to do some translation work. I've got some archive file orders out to a few companies currently, there have been some very interesting things with minimal English presence or English market entry delayed by a few years vs the German or Japanese market. There is a pretty interesting design from leitz that uses a scale and moveable reader that seems to have evolved into more modern digital indicators.
The big surprise is Olympus and their standalone head developments that they seem to have licensed out to other companies, but licensing information is in progress.
Most have been using a slit wheel like a modern computer mouse, but after some patents expired the design seems to have changed over to a scale based mechanism.
But anecdotes do help-just because I have found catalog entries and patents and sales brochures for the quality measurement systems and the moore & wright digital micrometers, does not really fill in any experiences of those who used it. A year apart, two different ideas for measurement yet extremely similar implementations and form factors.
For those into analog type micrometers, the r w carson design is amazing. He had that initial development at Westinghouse before individually putting together a several patent series for his micrometer, a tube based pressure control and eventually a motor drive. The 1940's brings what seems to be the origins of the lvdt probe in a micrometer as the measurement mechanism. Those aren't digital and are better documented, but they will be in the writeup since they're important ancestors.
I have seen the mitutoyo information, they come in a bit later but quite rapidly innovate and proceed to dominate the changes in digital micrometers starting mostly in the 80's. They do have earlier patents and designs but they seem to truly become the powerhouse they are starting in the 80's. It's unfortunate that their official history misses out on some of their early designs. Pulling out the truth from the modern advertisements, mitutoyo really does continue to produce some impressive micrometers and Japan seems to continue to be the main innovator in micrometers. There are some truly fascinating designs
At one point I had one of the Carson units and also an early Brown & Sharpe digital micrometer. My recollection is that B&S claimed it was the first of its kind.

One footnote to precision measurement and motion control was using synchronous motors and servos—so here in the US, 60-cycle current and various gears became a practical arbiter of precision for a bit.

Mechanical digital micrometers go back almost a hundred years. As soon as we had cheap displays, the rest was pretty much inevitable.
I ran a K&T 200 HMC with an "A" control, had a row of Nixie tubes as its readout.
K&T machines are classics. Those old readouts are amazing too, originating in dekatron counters in labs until the nixie and scales made them practical for a machine. Some of the first developments from Olympus microscopes of all places made use of these counting type displays. It's a little strange how the single integrated system in this era seems to have not been tried.

I think I have seen that Brown & Sharpe one, from my research initially though it seems they were later to the game, with what I can find as the first recognizable integrated unit as US3924336A which was assigned to a Japanese research company and used a glass scale. Some aspects seem slightly generic, but given the first alphanumeric segmented display was in the early 70's and not yet practical, it seems they expected display improvements and patented the idea. That would also explain why the mid 70's designs that were mass produced use a linear slide instead of a thimble.