🚀 go-pugleaf

In article <1i9j4gEINN8nd@uni-erlangen.de> mskuhn@immd4.informatik.uni-erlangen.de writes:
>Here for the aprox. 5% of the world population that don't use ISO paper sizes
>the dimensions of 3 of the most popular sizes:
>
>    A4    210 x 297 mm
>    C5    162 x 229 mm (envelope for A4 folded to A6 format)
>    DL    110 x 220 mm (envelope for A4 folded twice parallel)
>
>1 inch is 25.4000000 mm.

1 SI inch is 2.54mm _exactly_, not just to 7 decimal places.
But the people who don't use ISO paper sizes don't use SI inches
either, they use NIST inches, which differ from SI inches well before
the 8th decimal place.  (I don't know the exact details - after all,
why should I know about American internal standards?)

I believe NIST inches are a standard unit in HyTime.

Does the persistence of the NIST inch have anything to do with the
US public's huge stock of old guns needing new ammo machined to low
tolerances?  Britain had no problems redefining its Imperial measures
as SI multiples...  I wonder.

Markus Kuhn (unrza3@cd4680fs.rrze.uni-erlangen.de) wrote:

: Here for the aprox. 5% of the world population that don't use ISO paper sizes
: the dimensions of 3 of the most popular sizes:
: 
:     A4    210 x 297 mm
:     C5    162 x 229 mm (envelope for A4 folded to A6 format)
:     DL    110 x 220 mm (envelope for A4 folded twice parallel)
: 
: 1 inch is 25.4000000 mm.
            ^^^^^^
I thinked it was 25.412. Is it?
-- 
Nickolay Saukh

In article <1993Jan4.170125.3951@infodev.cam.ac.uk> ag129@cus.cam.ac.uk (Alasdair Grant) writes:
 > In article <1i9j4gEINN8nd@uni-erlangen.de> mskuhn@immd4.informatik.uni-erlangen.de writes:
 > >
 > >1 inch is 25.4000000 mm.
 > 
 > 1 SI inch is 2.54mm _exactly_, not just to 7 decimal places.
 > But the people who don't use ISO paper sizes don't use SI inches
 > either, they use NIST inches, which differ from SI inches well before
 > the 8th decimal place.  (I don't know the exact details - after all,
 > why should I know about American internal standards?)
 > 
Never knew this, but looked it up (in a British book, no less, from the
early 60s) and indeed, an US inch is ~25.4000509 mm (and not approx.
2.54 mm, Alasdair uses very small inches, or did he intend a deciinch?).
-- 
dik t. winter, cwi, kruislaan 413, 1098 sj  amsterdam, nederland
home: bovenover 215, 1025 jn  amsterdam, nederland; e-mail: dik@cwi.nl

ag129@cus.cam.ac.uk (Alasdair Grant) writes:

>In article <1i9j4gEINN8nd@uni-erlangen.de> mskuhn@immd4.informatik.uni-erlangen.de writes:
>>1 inch is 25.4000000 mm.

>1 SI inch is 2.54mm _exactly_, not just to 7 decimal places.
                  ^^ you mean centimeters (cm), don't you?

Of course, you are right. My intention was to write

    1 inch is 25.4000000... mm.     :-)

This inch is still used in metric europe for e.g. diameters of water
pipes and most dimensions in electronics are 2.54 mm (1/10 SI inch)
multiplied by something.

>I believe NIST inches are a standard unit in HyTime.

In HyTime (according to a recent CACM article) 1 inch is _exactly_
25.4 mm = 2.54 cm = 0.0254 m. Remember, HyTime is an ISO standard
and ISO standards only use the SI system defined in ISO 31.
(e.g. ISO 31-1:1978 Quantities and units of space and time)

Markus

-- 
Markus Kuhn, Computer Science student -=-=- University of Erlangen, Germany
Internet: mskuhn@immd4.informatik.uni-erlangen.de  |  X.500 entry available
----- Anyone participating in the use of MS-DOS, Heroin or Cocaine is -----
---- simply not getting the most out of life possible. (Brian Downing) ----

ag129@cus.cam.ac.uk (Alasdair Grant) writes:

>1 SI inch is 2.54mm _exactly_, not just to 7 decimal places.
>But the people who don't use ISO paper sizes don't use SI inches
>either, they use NIST inches, which differ from SI inches well before
>the 8th decimal place.  (I don't know the exact details - after all,
>why should I know about American internal standards?)

>Does the persistence of the NIST inch have anything to do with the
>US public's huge stock of old guns needing new ammo machined to low
>tolerances?  Britain had no problems redefining its Imperial measures
>as SI multiples...  I wonder.

The story I heard related to land title.

The whole of the contiguous United States has been surveyed from a
baseline on the East Coast. Changing the value of the inch even
slightly would create major hassles for landowners on the West Coast,
since land boundaries are defined by reference to survey points.

Does anyone from the US know anything about this?

Sean Case
--
Sean Case               gsc@coombs.anu.edu.au
"[...] if a poststructuralist doesn't get you,
 a deconstructionist will."--Ursula K. LeGuin

In article <1i9j4gEINN8nd@uni-erlangen.de> mskuhn@immd4.informatik.uni-erlangen.de writes:
}Here for the aprox. 5% of the world population that don't use ISO paper sizes
}the dimensions of 3 of the most popular sizes:
}
}    A4    210 x 297 mm
}    C5    162 x 229 mm (envelope for A4 folded to A6 format)
}    DL    110 x 220 mm (envelope for A4 folded twice parallel)

Printers in Germany and Japan use different sizes for the B series.
The German value is specified by DIN; I believe the Japanese value is
specified by some JIS standard:

        DIN             JIS    
B4      250x353         257x364
B5      176x250         182x257
B6      125x176         128x182
-- 
Tim Walters, Interleaf          uunet!leafusa!walters, walters@HQ.Ileaf.com

walters@HQ.Ileaf.COM (Tim Walters) writes:

>In article <1i9j4gEINN8nd@uni-erlangen.de> mskuhn@immd4.informatik.uni-erlangen.de writes:
>}Here for the aprox. 5% of the world population that don't use ISO paper sizes
>}the dimensions of 3 of the most popular sizes:
>}
>}    A4    210 x 297 mm
>}    C5    162 x 229 mm (envelope for A4 folded to A6 format)
>}    DL    110 x 220 mm (envelope for A4 folded twice parallel)

>Printers in Germany and Japan use different sizes for the B series.
>The German value is specified by DIN; I believe the Japanese value is
>specified by some JIS standard:

>        DIN             JIS    
>B4      250x353         257x364
>B5      176x250         182x257
>B6      125x176         128x182

That's strange news!

However, the DIN standard says that it is compatible with the ISO standard,
only the tolerances allowed by DIN are smaller than those allowed by ISO,
which isn't an incompatibility.

How have the JIS people defined the B series? In ISO and DIN, it is
just the geometric mean between two A series sizes (geometric mean of
a and b is sqrt(a*b)).

Still confused ...

Perhaps you mean the following: DIN/ISO define paper end formats. You write
'printers ... use'. Do you mean the size of the paper delivered to the printer
before it is sent to the offset printing machine and cut to e.g. B4? Ok,
that is not the 'paper end format' that is of interest for the common user.

Markus

-- 
Markus Kuhn, Computer Science student -=-=- University of Erlangen, Germany
Internet: mskuhn@immd4.informatik.uni-erlangen.de  |  X.500 entry available
----- Anyone participating in the use of MS-DOS, Heroin or Cocaine is -----
---- simply not getting the most out of life possible. (Brian Downing) ----

In article <1993Jan4.170125.3951@infodev.cam.ac.uk>
ag129@cus.cam.ac.uk (Alasdair Grant) writes:
>1 SI inch is [25.4 mm] _exactly_, not just to 7 decimal places.
>But the people who don't use ISO paper sizes don't use SI inches
>either, they use NIST inches, which differ from SI inches well before
>the 8th decimal place.  (I don't know the exact details - after all,
>why should I know about American internal standards?)

The official and legal measure system for the United States is, and has
been since the 19th century, the metric system.  (Little known fact, I
forget exactly where I read it.)  The US "imperial" system was defined
in terms of the metric system.  In this definition, 39.37 inches are
defined to be exactly 1 meter (metre).  If you invert this, you get
25.400050800101603 mm to the inch.

I do not know why the SI definition of an inch was changed from the
long-standing US definition.  I believe it was changed sometime around
1960.

-- 
  Lawrence Crowl		503-737-2554	Computer Science Department
			   crowl@cs.orst.edu	Oregon State University
	      ...!hplabs!hp-pcd!orstcs!crowl	Corvallis, Oregon,  97331-3202

In article <1ict41EINN7qk@uni-erlangen.de> mskuhn@immd4.informatik.uni-erlangen.de writes:
}walters@HQ.Ileaf.COM (Tim Walters) writes:
}>Printers in Germany and Japan use different sizes for the B series.
}>The German value is specified by DIN; I believe the Japanese value is
}>specified by some JIS standard:
}
}>        DIN             JIS    
}>B4      250x353         257x364
}>B5      176x250         182x257
}>B6      125x176         128x182
}
}That's strange news!
}
}However, the DIN standard says that it is compatible with the ISO standard,
}only the tolerances allowed by DIN are smaller than those allowed by ISO,
}which isn't an incompatibility.
}
}How have the JIS people defined the B series? In ISO and DIN, it is
}just the geometric mean between two A series sizes (geometric mean of
}a and b is sqrt(a*b)).
}
}Still confused ...

Sorry, I don't have the formal JIS standard, I only know that two
Japanese printers we have inhouse, from IBM and NEC, have B4 paper
trays with the above sizes. The manuals refer to a JIS standard, but I
haven't tracked it down.

}Perhaps you mean the following: DIN/ISO define paper end formats. You write
}'printers ... use'. Do you mean the size of the paper delivered to the printer
}before it is sent to the offset printing machine and cut to e.g. B4? Ok,
}that is not the 'paper end format' that is of interest for the common user.

I mean both the paper tray size and the paper size. I believe that B4
is a popular size in Japan. Could someone from Japan who knows more
about this shed some light on the issue?
-- 
Tim Walters, Interleaf          uunet!leafusa!walters, walters@HQ.Ileaf.com

[Alasdair Grant]
:
|   1 SI inch is 2.54mm _exactly_, not just to 7 decimal places.

There is no Systeme International "inch".

|   But the people who don't use ISO paper sizes don't use SI inches
|   either, they use NIST inches, which differ from SI inches well before
|   the 8th decimal place.  (I don't know the exact details - after all,
|   why should I know about American internal standards?)

"NIST" inches were aligned with the SI units well before 1982 (my earliest
reference to 1 inch = 2.54 cm), except for the US Survey foot, which is
~1.000002 ft, and reflects the old inch, for very sound reasons.

|   I believe NIST inches are a standard unit in HyTime.

The HyTime inch is 254/100 cm, or 2.54 cm, exactly.  There is no other
definition of inch in HyTime.  Of course.

Best regards,
</Erik>
--
Erik Naggum                 ISO  8879 SGML                    +47 295 0313
Oslo, Norway                ISO 10744 HyTime
<erik@naggum.no>            ISO  9899 C                 Memento, terrigena
<SGML@ifi.uio.no>           ISO 10646 UCS             Memento, vita brevis

In article <19930110.007@erik.naggum.no> Erik Naggum <enag@ifi.uio.no> writes:
 > [Alasdair Grant]
 > :
 > |   1 SI inch is 2.54mm _exactly_, not just to 7 decimal places.
 > 
 > There is no Systeme International "inch".
 > 
 > |   But the people who don't use ISO paper sizes don't use SI inches
 > |   either, they use NIST inches, which differ from SI inches well before
 > |   the 8th decimal place.  (I don't know the exact details - after all,
 > |   why should I know about American internal standards?)
 > 
 > "NIST" inches were aligned with the SI units well before 1982 (my earliest
 > reference to 1 inch = 2.54 cm), except for the US Survey foot, which is
 > ~1.000002 ft, and reflects the old inch, for very sound reasons.
 > 
Quoting from my basic reference on units %, subject yard:
	"... In England until 1963 the Imperial Standard Yard was the legal
	unit of length.  It was defined in the Weights and Measures Act of
	1878 as the distance between two points on a specified metal bar.
	In 1963 the yard was redefined as being equal to 0.9144 metres
	exactly.
	  In the United States the yard is specified by the Mendenhall order
	of 1893 as being equal to 3600/3937 metre and this makes the U.S.
	yard equal to 0.91440183 metres, i.e. it is about 0.7 * 10-4 inches
	longer than the 1963 Standard Yard.
	  In 1959 the International yard (0.9144 m) was adopted in the
	British Commonwealth and the United States of America for scientific
	purposes.  This yard has no legal status for trade but it is used as
	the unit of length both by the British Standards Institution and the
	American Standards Association.  The International yard is exactly
	the same as the British 1963 yard. ..."
What can we conclude?  The remarks of another poster chime with this (1 m =
39.37 US inch).  The US inch/foot is not only used for Survey but also in
Trade.  Only for scientific purposes the International inch is used.  The
US inch is *not* equal to the old Imperial inch.  While ASA (now ANSI)
standardized on the International Inch (for scientific purposes), I do
think that NIST did standardize the US inch.  The conversion factor Eric
gave is correct.  Now, while my reference is a bit outdated, I do not
think much has been changed.
--
%  H.G.Jerrard & D.B.McNeill, A Dictionary of Scientific Units.  Science
   Paperbacks, Chapman & Hall Ltd., London, 1966.
-- 
dik t. winter, cwi, kruislaan 413, 1098 sj  amsterdam, nederland
home: bovenover 215, 1025 jn  amsterdam, nederland; e-mail: dik@cwi.nl