Units of measurement

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
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.
 

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
 

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!:p

Phil
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
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!:p

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

rambojoe

Senior Member
Location
phoenix az
What, are they going to redefine pi as 3.00000 to make math easier? :D
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
Location
phoenix az
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.
 

broadgage

Senior Member
Location
London, England
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
Location
UK
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
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
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
Location
UK
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
Location
New England
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!:p

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