ECN Forum Forums General Topics of the Trade General Discussion Area US guys, do you use metric yet

Any system of measurement works as long as the guy making the other part also uses it. There is a big cost when one person uses their economic power to use one standard and everyone else uses another. Maybe when you finish off your economy properly we will be able to force metric upon you. Until then I guess we will buy two sets of tools and pray your pilots convert litres to pounds correctly. There isn't always a Canadian airport to catch the mistake ;-). Think how much cheaper your Chinese made in America Harley parts would have been if they used metric fasteners. Remember VHS vs Beta. Beta was better but the world chose VHS and even the most powerful consumer electronics company lost a lot of business in that war. You can be sure that even with it's world directing economic power that the US looses a lot of the world market by insisting on inches. Even on that specific scale 150mm sounds bigger than 6 inches. The adds would say add 50 by taking these little pills.

I get the impression that at last the metric system is starting to creep into the U.S, and a good thing too.
I've noticed on some television shows that some cars have the speedometers calibrated in km/h as well as mph. I sometimes wonder if this is an attempt to get U.S citizens used to metric units in a practical sense. I was told by a U.S school teacher on a visit that the metric system is taught there in schools.
Anyway, having grown up in Australia as the Imperial system was phased out starting in 1970, building materials still described in imperial units have almost gone.
I work on mechanical things and I'll tell you what, using imperial spanners is a pain. Having to stuff around with fractions working out what the next size spanner is requires converting back and forth between eights, sixteenths and quarters. Whereas if I want the next size up from 14mm, I look for 15mm; easy.

I suspect that has to do with so many building codes here that require studs on 16" centers and roof trusses on 24" centers. 4' and 8' just work out so well there.

Oddly enough Greg,
The centimetre, is the sort of "odd one out" over here.
I think the last time I used cm's was way back in Primary school.
Everyone that I know uses the milli-metre over here to measure things to any degree of accuracy.

In a way, the US has been incorporating Metric "Terms" into standard values for quite some time; i.e.:

• "Kilo" Volt-Amp,
• "Mega" Watt,
• "Milli" Amp,
• "Deci" Bels,
• "Micro" Farad.

In High School Physical Science, Metric values were used universally, without any requirements to convert results from SI Units to Imperial Units.
This was a great way to "become Metric fluent".

Most of the Construction-based Technical Documents (including the NEC), include SI values and "Standard Imperial".

Electrical Engineering is SI based, requiring Unit Conversions where applicable.
For me to determine wavelength, it is much easier to consider the value of "C" as 300,000 KM/S, as opposed to 186,000 Miles/S.

Illumination quantities - AKA "Lighting Levels", may be expressed as:
* Footcandles (Fc)
or
* Lux (Lx)
with a very simple conversion factor.

10 Fc = 100 Lx

To convert Lx to Fc:
Move the Decimal Point one space to the Left.

To convert Fc to Lx:
Move the Decimal Point one space to the Right.

Scott

I'd just like to add that we English did not invent the inch, even if we are big-heads about inventing everything else including the internet! Imperial simply refers to the 1824 Act of Parliament which attempted to make measures to be the same throughout the UK & Empire. By then the US had become independant, which is why your gallon is smaller than ours! The Act was primarily to stop people getting ripped off by short weights and confused by a plethora of different gallons, pints etc. The inch/foot can be traced back to before the time of the pharoahs, [3500BC] and is related to the cubit, [= about 1'6"]. The Romans bought the system to Britain in 44AD. It is in fact postulated that the cubit may have had its roots even earlier, in neolithic times. The builders of Stonehenge must have had measuring tools! One theory is that of the neolithic 'Venus Pendulum'. By timing the passage across the sky of Venus, using a pendulum bob over a 366 day cycle, you can not only get an accurate length base, [the neolithic yard], but an accurate astrological clock too, and discarded pendulum bobs are found at many megalith sites all over Northern Europe. Which is a bit more romantic than 1/10 millionths of the distance from the North pole to the Equator, via Paris, and then getting it wrong! I say long live the barley-corn, inch, foot, yard, pole, perch, furlong, chain, fathom, mile & league!

That's pretty much because electricity was discovered and developed after the Metric system was invented. Else we'd be dealing with Imperial measures of voltage, like "1 zapper = 2.54 volts" "We have 47 zappers on our powerlines in the USA". Thank heaven we don't have this silliness!

I think a lot of it boils down to the fact that the decimal system is in most cases considerably easier to grasp than fractions, except for the most simple ones like half and quarter (useful for measuring time, which isn't metric at all *g*). To me the idea that the human is a decimal being always made a lot of sense - we do have 10 fingers and toes each.

Those prefixes actually predate metric and even the birth of Christ. They are from ancient Greece.

Our ancestors were not a bunch of idiots with 12 fingers, they chose base 12 for practical reasons. It divides up better. 12 divides by 2, 3 and 6 in whole numbers. 10 divides by only 2 and 5.
Our old British money was base 12 too- 12 pennies per shilling, making shopping easy.
They still sell eggs in dozens, even in France!