Author Topic: Measurement Terminology  (Read 6975 times)

Offline Homebrewer

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Measurement Terminology
« on: June 24, 2017, 01:22:00 AM »
Hi all!  I've been lurking for a while.  I'm mainly here to read and learn since I'm  couped up in a 3rd floor apartment and have no room for hobbies. 

In reading as many forum posts as I do around the Interwebs, I notice there a great many citizens of The Commonwealth who dabble in machining.  What I find interesting is that you gentlemen seem to alternate back-and-forth between Metric and Imperial measurement quite frquently. 

I am curious: is Imperial measurement still taught outside the US? Or is it simply a relic of a bygone era that's just carrying over to today?  I've been to Canada a few times and all the measurements I saw there were metric.  I had the metric system drilled into my head in grade school so I understand it...and one's as good as the other I suppose.  I guess I'm just commenting on something I find curious.

Cheers,

Jason

Offline chipenter

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Re: Measurement Terminology
« Reply #1 on: June 24, 2017, 02:01:50 AM »
I lerned on inperial but it depends on wich side of a tape I use .
Jeff

Offline SwarfnStuff

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Re: Measurement Terminology
« Reply #2 on: June 24, 2017, 02:11:53 AM »
Hi and welcome Jason.

        Here is OZ everything is metric and originally they wanted to stop the sale of imperial rules etc. Didn't last too long.
        Being of the old codger age I swap back and forth but much prefer metric. Everything is divisible by 10, just keep track of the decimal point though.

        I also had the advantage of working in a textile laboratory and although initially we used Oz drams etc we went metric way before the government thought it a good idea. All science labs that I know of are metric oriented.

As I understand it the USA is officially metric but many choose to stay with imperial.

That said, I think that Australia (OZ) is only one of three countries in the world that drive on the left of the road. Could easily be wrong on that score though.
Welcome again.

John B
Converting good metal into swarf sometimes ending up with something useful. ;-)

Offline awemawson

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Re: Measurement Terminology
« Reply #3 on: June 24, 2017, 02:19:29 AM »
Japan, Malta, U.K.,Australia are LHD and I suspect that there may be a few others, possibly the Falkland Islands and Ascension Island, also maybe Tristan da Cunha ?
« Last Edit: June 24, 2017, 04:47:44 AM by awemawson »
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Offline howsitwork?

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Re: Measurement Terminology
« Reply #4 on: June 24, 2017, 02:23:31 AM »
Isn't Ireland LHD as well?

Offline AdeV

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Re: Measurement Terminology
« Reply #5 on: June 24, 2017, 05:26:15 AM »
India, South Africa.... they drive on the left. There's a list here: http://www.rhinocarhire.com/Car-Hire-Blog/August-2009/Which-Countries-Drive-on-the-Left,--a-Handy-Guide.aspx

When I went to secondary school in 1984, we were taught exclusively metric. However, the rest of the country still used largely imperial measures, so I'm basically of the bilingual age. When I'm making stuff, I'll often mix units through the build, so anything on the lathe gets measured and cut in imperial, anything on the CNC machine gets designed in French - er, metric.

When it comes to distances or speeds, I intuitively think in imperial (inches, feet, yards and miles), temperatures and weight in metric. e.g. when someone says he weighs 220lbs, I have to use a conversion calculator to work out if he's fat or not...
Cheers!
Ade.
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Offline Pete W.

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Re: Measurement Terminology
« Reply #6 on: June 24, 2017, 05:49:46 AM »

SNIP

     e.g. when someone says he weighs 220lbs, I have to use a conversion calculator to work out if he's fat or not...
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest design change-note!

Offline vtsteam

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Re: Measurement Terminology
« Reply #7 on: June 24, 2017, 09:49:55 AM »
Schizophrenic here, too:

When building very small models I usually weigh them as I build them, in grams.

Larger models I switch to ounces.

Materials density for foam sheets of different brands, covering paper, and other things I use to build with, I compiled a whole spreadsheet for my own use calculating grams per square inch.

I still think of wing area in relative terms of square inches. That's probably because I know how much wing area a great number of models have in square inches -- dating back 50 years, so by comparison, if building something new that mental database is useful. And the square inch is a useful size to keep model wing area in the hundreds, so mental arithmetic feels easier to me when calculating.

I do mental conversions of mm to inches on plans (for approximate size glomming) by multiplying by 4, and moving the decimal point over 2 places. That I can do in a second or two.

I still use sixty seconds in the minute, 60 minutes in the hour, and 24 hours in the day......

Having admitted all the above, I absolutely do not want to defend the imperial system, or the metric system in one of those ten (or twelve!) to the 6th power online arguments about "which is better". I have many ancient Model Engineer magazines where metrication (or metrification) was fervently argued in reader mail, as well.

Me, I am quirky, and use whatever feels most comfortable, but wouldn't inflict that on another!  :beer:

I love it when a Plan B comes together!
Steve
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Offline Mike E.

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Re: Measurement Terminology
« Reply #8 on: June 24, 2017, 12:17:01 PM »
"Imperial" is my first language in regard to measurement. I find it easier to think in inches, feet, and thousandths of an inch.  It works just fine for my needs, and also, all of my manually operated shop equipment was designed to use Imperial measurements. I am ambidextrous, so I can work in metric if the need arises. As for other forms of measurement terminology, I'm still trying to figure out "how high is up" ?   :scratch:
Mike

California & Wales  - Home, & Home Away

Offline Spurry

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Re: Measurement Terminology
« Reply #9 on: June 24, 2017, 12:58:01 PM »
I think in imperial but try to only work in metric. A chippie (carpenter) I worked with at one time would use whole metres, and rest of measurement in inches, so for instance would measure a piece as being 4metres and 7 3/4 inches.
Pete

Offline ieezitin

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Re: Measurement Terminology
« Reply #10 on: June 24, 2017, 01:21:27 PM »
Hello homebrewer,

ill be brief.. you can take up a machining hobby in your apartment  an example would be a watch / clock maker could fit his machines and tooling in the corner of a bedroom you have.

I am an ex-patriot from England living here in the states now for 25 years yet for all of this time its always perplexed me that Americans always say they don't understand the metric system yet their currency is.

It was my career that brought me here I am in the construction & engineering side of oil refineries that are still heavily entrenched in the Kings system on a global scale, yet when i interact with highly skilled and educated engineers they all piss and moan on cross referencing metric to imperial… they even say they don't get it.. To me it's just being lazy after all they had to pass the math test to get the diploma, I think this is mainly the largest reason why the US is one of only a handful of nations not on the metric system.

It's all about standards and there is two used throughout the world understanding them both just takes the understanding why they exist, I believe the metric system format is broader because it covers more disciplines yet the kings is still widely used as they are tied to the world's largest industries mainly the largest which is mining and agriculture Hence the United States stalwart clinging on to the Kings. .
 
Liters, meters, microns fit into disciplines heavily studied after the mid 17th century, weights, volume, horsepower were all prevalent before plus some of the greats designed the structure as they were born in this era. If you notice too both systems were derived by two nations heavily involved in world imperialism France and England.
 
Saying all that I boil and render it down simply as this... both systems have one common denominator “ excuse the pun” shared by both, they use the same universal  language math.. Its secret is understanding one thing the decimal point.. Comprehension of this tiny little speck makes you a master in both systems.
 
Hope this helps clear things up..
 
Anthony.

... Homebrew. i don't want you to think i took what you wrote as you are pissing and moaning, I did not mean this in my statement i was generalizing... just wanted to clear this up..

Anthony.
« Last Edit: June 24, 2017, 02:42:34 PM by ieezitin »
If you cant fix it, get another hobby.

Offline vtsteam

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Re: Measurement Terminology
« Reply #11 on: June 24, 2017, 07:05:12 PM »
its always perplexed me that Americans always say they don't understand the metric system.....
......when i interact with highly skilled and educated engineers they all piss and moan on cross referencing metric to imperial… they even say they don't get it.. To me it's just being lazy after all they had to pass the math test to get the diploma, I think this is mainly the largest reason why the US is one of only a handful of nations not on the metric system.

Americans always....
engineers all....
piss and moan.....
lazy......

This road is about 1 meter long. In other words, a short one. Might be best not to start down it.
I love it when a Plan B comes together!
Steve
https://www.youtube.com/watch?v=4sDubB0-REg

Offline Lew_Merrick_PE

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Re: Measurement Terminology
« Reply #12 on: June 24, 2017, 08:46:40 PM »
i admit that I hate the "unit" the Newton and all "units" that derive from it!  However, having purchased a large and expensive set of sub-micron micrometers and dial indicators in 1968, I was burned by the 1969 redefinition of the metre.  The changeover from Centigrade to Celsius of the early-1970's (not being certain of the year) to change 0°C for the "improved" triple-point of water also affected me.

As the senior mechanical design engineer on the program the developed automotive airbag restraint systems, it was the engineers from Japan and Germany who had the most problem with exploding inflators because of the rapid change in units across Pascal (pressure) measurement!  American engineers using psi had virtually no such problem.  I forget which year it was, but we crashed a "Mars probe" because the ESA assumed that accelerations were measured in m/sec˛ rather than gravitles (the "standard" since Goddard's day).

When I do work for German agencies and companies, the use of kgf is required.

Offline tom osselton

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Re: Measurement Terminology
« Reply #13 on: June 24, 2017, 11:42:47 PM »
 I remember that mars probe.... A lot of coin just to make a pancake! But that is why we have the lowest bidder right? From what I remember both Canada and the USA were changing to metric at the same time but the Americans thought it was too costly to change all the signage. Course I could be wrong its what I was told. There also wasn't much metric in school either I think we had a couple of weeks of it.

Offline PekkaNF

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Re: Measurement Terminology
« Reply #14 on: June 25, 2017, 02:30:17 AM »
Metric or imperial? Best system is what you are used to. I'm from Finland and we are metric to the core.

However, much of the old (farming) stuff was british (with their withworth thread and imperial units, some stuff was american (UNF/UNC bolts and their understanding of imperial unis). Some tractors hand mixed fasteeteners. Tire /Wheel size is still mixture of the unists like 15" rim and rest in metric.

Building boards were metric as far as I can remember, but I remember when lumber was defined often in incehes like 2x4". Coarse units seem to work well on rough work.

We used to make some machine in imperial dimenssions for american market. It was a mess, materials had to be imperial or there was waste, some sizes were easy to adjust, some not. But engineers can do bolt paterns and use prefered size tables withhout moaning. We stoped doing them when american buyers stopeed insisting on them.

Best part was one canadian customer, we delivered there a proction line, metric off sourse. They had some imperial stuff and delivered nearly half their production to USA (some in metric dimenssions and some not). We have pretty mutch math and program in the PLC and then a user interface to control the procutiont. We can scale the user intercase to foreign unist/accuracy. They wanted one dimenssion input in inches and all the others in metric - all resuslts had to be shown in in metric (mill computers and information system was metric so were the orders, imperila units were on "info field"). The the system was build to certan accuracy and display reflected that. They took the metric display as a gospel, but said that the inches looks like they have way too many digits.....although they were correct and accurate conversion.

I don't use imperila units, I convert them. I have an idea what bolt sizes and AF are, I still have set of imperila tools, left from couple of yeras for maintaing my Harley (1984 late model FXST). BUT if i need to something for a hobby building I try to find metric drawing and if the fails, I'll do a doodle that has inch/mm main dimenssions and see how that needs to be adjusted on metric material and thread sizes. I much prefer German drawings, not only because they are metric, but also the materials make sense to me and find them easier to read.

This is my history, everybody has a diferrent story.

Pekka

Offline joshagrady

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Re: Measurement Terminology
« Reply #15 on: April 11, 2018, 02:10:27 PM »
Being raised and educated in the US, but having spent essentially all of my adult life in Europe, I also switch back and forth without much problem.  (The exception being temperature; as a more visceral measurement, I intuitively know that 95°f feels hot, but have to think about whether 35°c will make me sweat.)
One huge advantage I've found to the imperial system is that, when doing an installation on site, I don't have to worry about my imperial tape 'growing legs', whereas metric tapes disappear quickly if one isn't careful.  Spaniards quickly learn not to ask to borrow my tape measure.  :lol:

Offline AdeV

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Re: Measurement Terminology
« Reply #16 on: April 11, 2018, 02:39:20 PM »
I'm currently reading a fascinating book called "Measuring America", by Andro Linklater. Seems one Thomas Jefferson (I imagine most Americans will know who he is without any introductions...), who spent considerable time in France and was tasked with reforming the USA's exceedingly haphazard and non-standardised Weights and Measures (and currency), proposed a decimal system of feet and inches (10 inches to the foot) based on a rod which, when suspended from one end and set swinging like a pendulum, would have a frequency of exactly 1/2Hz (i.e. 1 second to swing fully to one side, 1 second to swing back again).

I haven't got far enough through the book to find out what happened next, but I can recommend it to anyone who's interested in why the USA is divided up as it is, and how its measurement system came to be!
Cheers!
Ade.
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Offline awemawson

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Re: Measurement Terminology
« Reply #17 on: April 11, 2018, 03:27:51 PM »
" Frequency of a pendulum is One over two pi  times root L over G, so period is Two Pi times root L over G"

Amazing how things things pop back into your brain from physics lessons 50 years ago - the teaching then obviously worked  :lol:
Andrew Mawson
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Offline Biggles

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Re: Measurement Terminology
« Reply #18 on: April 12, 2018, 01:32:43 AM »
Like John B I am an old codger, schooling was Imperial and metrification came latter. I have no problems with Metric measurements except that I am easier thinking Imperial. I can picture a foot but I find it a little more difficult in picturing 300mm.  :loco:

Offline SwarfnStuff

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Re: Measurement Terminology
« Reply #19 on: April 12, 2018, 02:35:11 AM »
Guess what Biggles?
           I see 300mm and think, "Foot" Likewise 150mm becomes 6" etc. It's just how I picture them in my mind, but happily go on to measure and machine in metric.
    The real fun begins when I get imperial plans and set about multiplying everything by 25.4 to get mm, bolt / screw holes get changed to the nearest metric size as I don't posses imperial fasteners nor the taps / dies to form them. Then remember to adjust things for the minor differences, or forget to do so and confuse myself later.
         Temperature stays metric, To be fair to Mr Fahrenheit, he at least knew that there were temperatures below freezing water.
John B
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Offline Lew_Merrick_PE

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Re: Measurement Terminology
« Reply #20 on: April 12, 2018, 12:50:33 PM »
To be fair to Mr Fahrenheit, he at least knew that there were temperatures below freezing water.

Actually, Dr. Fahrenhrit was concerned with sailors.  0°F is the temperature when Baltic Seawater froze to a ship's rigging making it too dangerous to climb and handle.  100°F is the body temperature when a sailor should not be expected to perform "deck work."

Offline joshagrady

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Re: Measurement Terminology
« Reply #21 on: April 13, 2018, 03:28:14 PM »
I'm currently reading a fascinating book called "Measuring America", by Andro Linklater. Seems one Thomas Jefferson (I imagine most Americans will know who he is without any introductions...), who spent considerable time in France and was tasked with reforming the USA's exceedingly haphazard and non-standardised Weights and Measures (and currency), proposed a decimal system of feet and inches (10 inches to the foot) based on a rod which, when suspended from one end and set swinging like a pendulum, would have a frequency of exactly 1/2Hz (i.e. 1 second to swing fully to one side, 1 second to swing back again).

I haven't got far enough through the book to find out what happened next, but I can recommend it to anyone who's interested in why the USA is divided up as it is, and how its measurement system came to be!
Along those lines, I'd recommend One Good Turn by Witold Rybczynski -- a fun history of the development of the screw, and of thread cutting machines.

Offline Pete.

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Re: Measurement Terminology
« Reply #22 on: April 13, 2018, 05:46:00 PM »
Hi all!  I've been lurking for a while.  I'm mainly here to read and learn since I'm  couped up in a 3rd floor apartment and have no room for hobbies. 

In reading as many forum posts as I do around the Interwebs, I notice there a great many citizens of The Commonwealth who dabble in machining.  What I find interesting is that you gentlemen seem to alternate back-and-forth between Metric and Imperial measurement quite frquently. 

I am curious: is Imperial measurement still taught outside the US? Or is it simply a relic of a bygone era that's just carrying over to today?  I've been to Canada a few times and all the measurements I saw there were metric.  I had the metric system drilled into my head in grade school so I understand it...and one's as good as the other I suppose.  I guess I'm just commenting on something I find curious.

Cheers,

Jason

If you mean 'in schools' then in the UK the inch system is not taught in mainstream. As a matter of fact I met a site engineer working on a rail project who asked for a 200mm diameter hole to be drilled in concrete. When I later referred to it as an 8" hole he had no clue what I was on about. He couldn't even tell me what the standard gauge of a railway line was (which is specified in feet and inches) - and he was working on the railway :D

Offline bpud

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Re: Measurement Terminology
« Reply #23 on: April 18, 2018, 11:49:04 PM »
I grew up in the UK in the 60s, and now live in Australia.  I'm bilingual in both Imperial and Metric, but much prefer Metric.  However, in the early 70s I was a Work Study Engineer, and we used decimal minutes, i.e 1.50 minutes = 1 minute 30 seconds.  It made so much sense especially when crunching the numbers!!  However I've never heard of decimal minutes being used anywhere else, maybe someone has??
cheers
Bill