Units of measurement

Senior Member
I tell you.. 45 mm is easier to find than 1-11/16ths inches... at least for me...

Tony S

Senior Member
So was our method of timekeeping.
It caused some confusion.

This clock is on Bristol corn exchange. The first minute hand is Bristol time, the second minute hand is GMT.

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ggunn

PE (Electrical), NABCEP certified
It caused some confusion.

This clock is on Bristol corn exchange. The first minute hand is Bristol time, the second minute hand is GMT.

View attachment 21404
But coordination of railroad schedules is what drove the establishment of time zones rather than having each locale calibrate their clocks to solar time.

Tony S

Senior Member
There is one standard of weight used the world over, the troy ounce. One troy ounce = 1.0971 Avoirdupois ounce or 31.1034 grams.

1 Troy pound = 12 troy ounces.

Used for bullion transactions.

Phil Corso

Senior Member
Tony...

Sorry, but multiplication by constants must be used in a certain direction to convert kg to oz(t)! For example you can't go the short way from kg -> lb (avoir'), lb(avoir') -> lb(t), lb(t) -> oz(t), using just 3 constants !

Instead, multiplication must go from kg -> g, g -> mg, mg -> scruple, scruple -> pennyweight, pennyweight -> dram(t), dram(t) -> oz(t) (requiring 7 constants)!

Let me know if there is a need know the multiplication constants (5 have no decimals, one has 1 decimal, and 1 has 5 decimals)!

Regards, Phil Corso

peter d

Senior Member
I'll give up imperial when you pry it out of my cold, dead hands.

drcampbell

Senior Member
Progress is sometimes achieved slowly -- one funeral at a time.

chris1971

Senior Member
I know I have brought this topic up before.
Will the US ever join the rest of the world and move to using SI units of measure?
For example, is there any sense in two different units for power?

And AWG is baffling in its derivation.

https://en.wikipedia.org/wiki/American_wire_gauge
Works great here. Why change it? Maybe the rest of the world should adopt our standards.

peter d

Senior Member
Works great here. Why change it? Maybe the rest of the world should adopt our standards.
:thumbsup::happyyes:

Phil Corso

Senior Member
Peterd...

I believe your hope to keep American practice in measurement-standards is about to be dashed! Next month reps from 57 countries will meet in France to change SI-units in the most profound way since the French evolution!

Phil

ggunn

PE (Electrical), NABCEP certified
Peterd...

I believe your hope to keep American practice in measurement-standards is about to be dashed! Next month reps from 57 countries will meet in France to change SI-units in the most profound way since the French evolution!

Phil
What, are they going to redefine pi as 3.00000 to make math easier?

rambojoe

Senior Member
What, are they going to redefine pi as 3.00000 to make math easier?
calculating Japanese engine displacement will not work if you don't round up (I know,,,) to 3.1417, as opposed to 3.1416- oddly enough. I believe Italian machinery is the same but not sure about American motors. just letting yall know

rambojoe

Senior Member
I'm sure the 750 is most likely 750 cubic centimeter of displacement as well.
might even be 746... and in 2-strokes there is huge debates on what math to use- whether the stroke is measured from the top of the exhaust port or the usual full piston travel. again, I know, kinda useless info for lots but full on debates (and interesting) for less.

Senior Member
I would in general prefer metric/SI units.

To me the major advantage is that these units are the same everywhere. Many older measures have regional, national or application specific variations.

A kilometer is always the same, a mile varies a bit, imperial, nautical, or railway ?
A liter is likewise the same everywhere, whereas US and UK gallons are significantly different.

Some peculiar measures were simply used to cause confusion and have largely disappeared. Chemicals used to be supplied in large bottles that held a "wine gallon" or a "reputed gallon" liters now
Sprits in a bar used to be served in measures of "one sixth of a gill" 25ml now.

One old measure that survives is the "ligne" pronounced as line, and sometimes written thus these days. It is used to denote the size of an oil lamp burner. "a two ligne burner is fine for a nightlight, but reading requires at least a 16 ligne burner. A ligne is one twelfth of an inch.

Large volumes of water in the USA are often measured in "acre feet" a term almost unknown in the UK.
Acre feet sounds to me more like an animal ailment ! "poor beast was suffering from acre feet, and had to be shot, to prevent suffering"

Besoeker

Senior Member
I would in general prefer metric/SI units.

To me the major advantage is that these units are the same everywhere. Many older measures have regional, national or application specific variations.

A kilometer is always the same, a mile varies a bit, imperial, nautical, or railway ?
A liter is likewise the same everywhere, whereas US and UK gallons are significantly different.
Universal (almost) and consistency are the merits for me.

ggunn

PE (Electrical), NABCEP certified
Universal (almost) and consistency are the merits for me.
For me it would be that the math is straightforward. Simple addition, subtraction, multiplication, and division would be so much easier to get right without having to deal with, for example, miles, feet, inches, and fractions of inches.

Besoeker

Senior Member
For me it would be that the math is straightforward. Simple addition, subtraction, multiplication, and division would be so much easier to get right without having to deal with, for example, miles, feet, inches, and fractions of inches.
That's it in a nutshell. Simpler.

LarryFine

Master Electrician Electric Contractor Richmond VA
might even be 746... and in 2-strokes there is huge debates on what math to use- whether the stroke is measured from the top of the exhaust port or the usual full piston travel. again, I know, kinda useless info for lots but full on debates (and interesting) for less.
I would say full stroke for displacement but port-to-TDC for compression ratio.

peter d

Senior Member
Peterd...

I believe your hope to keep American practice in measurement-standards is about to be dashed! Next month reps from 57 countries will meet in France to change SI-units in the most profound way since the French evolution!

Phil
Like I said, they can pry my fractional tape measure out of my cold, dead hands.