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Question about imperial units

Started by July 25, 2011 07:19 PM
31 comments, last by way2lazy2care 13 years, 3 months ago
[quote name='Hodgman' timestamp='1311654597' post='4840378']For perspective ..... For a non-american [who uses variations of [font="Courier New"]m[/font]]... Visualising [feet and inches and acres is] complex ...
It's only complex because you've never used it. If you grow up your whole life listening to people talk about their heights, it isn't complex at all. It's only complex when you aren't used to it.[/quote]Ugh. Yes. That is why.

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Yeah water boils at 100 celsius and freezes at 0, but how hot is 30 degrees?[/quote]30+ is a nice summer day smile.gif 40+ is a sweltering summer day. 50+ is a die-of-heat-stroke day. 20+ is room temperature. 10+ is a cool day. 0+ is a very cold day. Minus anything is a frozen day.
140 is a slow cooking temperature. 180 is moderate. 220 is very hot.
You are now accustomed to degrees Celsius! biggrin.gif
[size="1"]N.B. subjective interpretation of temperature affected by locale of reference.

Has anyone worked with construction measurements in the US? Do you just use inches (and fractions of inches) for everything? Or do you mix other measurements in too?



Unless metric is being mandated for some reason, measurements are typically given in feet, inches, and fractions of an inch. E.g. 21' 1-1/2" And yes, it can be confusing, even after working with it every day. Surveyors (and to a lesser degree, civil engineers) typically use decimal feet, e.g. 21.12'. Rarely do things need to be measured during typical construction which have a tolerance of less than 0.01 of a foot.

As I hinted above, the problem I have with fractional inches is that it hides precision: given 21.12', I can be sure of what the sought after precision is (but not necessarily the accuracy), but with 21' 1-1/2", an architect may just be rounding off to the nearest 1/2" and I would never know (this happens occasionally and does cause problems).
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The measurements all make sense when you look at how they came about. A mile is 8 furlongs. The reason it is 8 dates back to Romans having 8 stade in their mile, which was originally 1000 roman paces. The yard is most likely related to the distance of an average pace. Horses are measured in Hands because everyone has hands and can easily approximately measure horses. Inches have similar origin to ounces as they both derive from latin's one twelfth.

An acre is the approximate measure of the land one man and one ox could plow in one day.

Farenheit degrees is slightly more complicated, but it takes other things into account that the celsius scale does not and was also created before the metric system decided to use water as it's baseline for most of it's measurements.

The weirdness is much more to do with all these measurements which make perfect sense with their original uses being converted to other units with completely different uses.

Farenheit degrees is slightly more complicated, but it takes other things into account that the celsius scale does not and was also created before the metric system decided to use water as it's baseline for most of it's measurements.


Fahrenheit is a good measurement of human tolerances. Greater than 100 degrees and you are definitely in danger territory for heat stroke. 32 degrees is freezing, but it's much of a hindrance for most people. Things don't get really uncomfortable until you're below 0 Fahrenheit (When I lived in Iowa, after winter, just above "freezing" was shorts weather). It's not uncommon for most places in the USA to reach these temperatures throughout the year.

0+ is a very cold day.
[size="1"]N.B. subjective interpretation of temperature affected by locale of reference.


Very subjective.

0+ is a cool to chill day, but still acceptable shorts weather if you don't plan to be outside for extended periods of time.


Personally I use feet, inches, and fractions of an inch for construction. But I only do that because 90+% of building materials sold in Canada are still cut to Imperial measurements. (This is for economic reasons. Mills producing stuff here can then produce the same stuff and ship it down to the US Market, and we can buy materials off the US Market without getting weird looks when we ask for something in cm.)


The moment metric cut materials become common here, I'll toss my imperial tapes in the back of the tool box and forget about them.
Old Username: Talroth
If your signature on a web forum takes up more space than your average post, then you are doing things wrong.

Fahrenheit is a good measurement of human tolerances. Greater than 100 degrees and you are definitely in danger territory for heat stroke. 32 degrees is freezing, but it's much of a hindrance for most people. Things don't get really uncomfortable until you're below 0 Fahrenheit (When I lived in Iowa, after winter, just above "freezing" was shorts weather). It's not uncommon for most places in the USA to reach these temperatures throughout the year.

It's actually loosely based off of the body temperature of a horse, which has a more stable body temperature than a human.

TheMoreYouKnow.jpg
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[quote name='Hodgman' timestamp='1311687526' post='4840511']
0+ is a very cold day.
[size="1"]N.B. subjective interpretation of temperature affected by locale of reference.


Very subjective.

0+ is a cool to chill day, but still acceptable shorts weather if you don't plan to be outside for extended periods of time.


Personally I use feet, inches, and fractions of an inch for construction. But I only do that because 90+% of building materials sold in Canada are still cut to Imperial measurements. (This is for economic reasons. Mills producing stuff here can then produce the same stuff and ship it down to the US Market, and we can buy materials off the US Market without getting weird looks when we ask for something in cm.)


The moment metric cut materials become common here, I'll toss my imperial tapes in the back of the tool box and forget about them.
[/quote]

If you're tapes don't have metric and imperial measurements, you bought the wrong ones. I haven't purchased a ruler or tape measure without both since I was in kindergarden. Even my Gerber multitool which has barely enough room to write the numbers has metric and imperial units.

[quote name='tstrimple' timestamp='1311691843' post='4840561']
Fahrenheit is a good measurement of human tolerances. Greater than 100 degrees and you are definitely in danger territory for heat stroke. 32 degrees is freezing, but it's much of a hindrance for most people. Things don't get really uncomfortable until you're below 0 Fahrenheit (When I lived in Iowa, after winter, just above "freezing" was shorts weather). It's not uncommon for most places in the USA to reach these temperatures throughout the year.

It's actually loosely based off of the body temperature of a horse, which has a more stable body temperature than a human.
[/quote]

History of Fahrenheit

Regardless, I didn't say what it was based on, I said it was a good measurement for human tolerances.
I've also wondered why certain numbers were chosen historically (such as the 12 inches per foot rule), but I could never be bothered to really research it.

I've come to be comfortable with both systems, as I had to learn the SI system in school and apply it enough in labs that it's become second nature. The inner scientist in me greatly prefers the elegance of the SI system, but everyone around me uses the typical US system so I rarely apply the SI system to anything.

I really wish the movement to convert over to the SI system hadn't petered out like it did. After all, didn't we lose a rocket recently because someone failed to do the conversion work?
Success requires no explanation. Failure allows none.

[quote name='Luckless' timestamp='1311692028' post='4840564']
[quote name='Hodgman' timestamp='1311687526' post='4840511']
0+ is a very cold day.
[size="1"]N.B. subjective interpretation of temperature affected by locale of reference.


Very subjective.

0+ is a cool to chill day, but still acceptable shorts weather if you don't plan to be outside for extended periods of time.


Personally I use feet, inches, and fractions of an inch for construction. But I only do that because 90+% of building materials sold in Canada are still cut to Imperial measurements. (This is for economic reasons. Mills producing stuff here can then produce the same stuff and ship it down to the US Market, and we can buy materials off the US Market without getting weird looks when we ask for something in cm.)


The moment metric cut materials become common here, I'll toss my imperial tapes in the back of the tool box and forget about them.
[/quote]

If you're tapes don't have metric and imperial measurements, you bought the wrong ones. I haven't purchased a ruler or tape measure without both since I was in kindergarden. Even my Gerber multitool which has barely enough room to write the numbers has metric and imperial units.
[/quote]

No, I very much bought the correct tapes, scales, and rulers. The first thing I do when I get a tape that has both metric and imperial is toss it out and go looking for a real tool. A dual marked tape is a tape that you can only measure from one side of.

When you measure for construction or drafting, you measure from base lines. If you have your tape hooked at the base line and are marking out points on the floor, then a double scaled tape means that you possibly have the wrong scale against where you are marking, and then you're kind of eye balling your lines.

For what reason would you ever want both imperial and metric at the same time? I've been around construction sites since I was about 5, and in those 20 years I've yet to use a metric tape on a job site for anything other than assembling precision equipment that was designed in metric.
Old Username: Talroth
If your signature on a web forum takes up more space than your average post, then you are doing things wrong.

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