The numbering schemes on metric measuring tapes is not American vs. European
issue. American-brand tapes such as Stanley, which are widely sold in the
metric countries too, come in at least four different numbering styles:
(1) A straightforward numbering of centimeters. I agree with Joe that this
is the simplest, most legible, and easiest to read system. It is the most
common layout in BOTH the U.S. and Europe. For example, 365 would be
pronounced "three sixty-five" meaning BOTH "three [hundred] sixty-five
[centimeters]" and "three [point] sixty-five [meters]". You can record it
either way without changing the way you pronounce it. No mental exercise
required.
However, because the construction industry in the English-speaking countries
(UK, Canada, Australia, and now US) has suppressed centimeters, tapes
numbered in millimeters are also in use. They are of two types:
(2) The scheme Joe described has 2- (or sometimes 3-) digit
millimeter-numbers every centimeter, plus whole-meter numbers on a separate
row/color every decimeter. I agree with Joe that these are awkward to read.
The rationale for them is that four-digit numbers would be too crowded, so
they put the first digit on a separate row. This type of tape is usually
read as meters-and-decimals, or as thousands and hundreds of millimeters
(very clumsy).
(3) The scheme I described, with 4-digit mm numbers every decimeter, and
only the final 2 digits every centimeter (all on the same row). Pat says
this is the most common type tape in Australia, and they are also available
here.
(4) A layout used on long fiberglass surveyor's tapes (where precision is
not great), with whole meters numbered every decimeter in one color (or
row), with centimeters (0 through 90) numbered every decimeter in a second
color (or row), and the single smaller digit "5" at the 5 cm intervals.
These are also awkward to read, and invariably read as meters-and-decimals.
There is the problem with very long (>10 m) but narrow reel-type tapes of
where to put the extra digit. A centimeter tape would require 4 digits (very
crowded, and possible only every decimeter at best) whereas a millimeter
tape would require 5 digits (impossible unless the figures were minuscule.
I've never seen such a long millimeter tape).
The most legible tape (i.e., largest fonts, fewest digits, and fewest
unnecessary zeroes) would be one numbered in decimeters, with smaller
single-digits every centimeter. This would allow fonts as large as those on
wombat tapes. But as far as I know, decimeters have never been used anywhere
and I am not suggesting they be introduced. However, style #3 above is often
read like decimeters, with the word "hundred" in lieu of the word
"decimeter". For example,
1500 [mm] is usually pronounced "fifteen hundred" (= 15 dm), not as "one
thousand five hundred"
1650 [mm], which actually appears on the tape as 1600 + 50, is usually
pronounced "sixteen [hundred] fifty" (= 16.50 dm), not as "one thousand six
hundred fifty"
I can imagine American workers dropping the word "hundred" in casual speech,
in which case these expressions would be identical to decimeters. This would
greatly simplify the names of modular parts, which are all whole decimeters.
A sheet of plywood or drywall would then be called 12 x 24 or 12 x 36
(decimeters or hundreds of millimeters being understood). These would be
very comfortable to Americans used to dealing in 12s. Concrete block sizes
would be 2 x 2 x 4, or 1 x 2 x 4, and so on--simpler than the wombat
versions. Of course, decimeters wouldn't be convenient for small non-modular
objects <100 mm. In those cases, I imagine the unit would either be
pronounced or understood from the context. For example, Pat says that in
well-metricated Australia, the word "millimetre" is always used with pipe:
it's "twenty millimetre pipe" never "twenty pipe". But he also says that
Australian workers always pronounce the "hundred" in dimensions.
In any event, these problems are minor compared to wombat tapes and rulers,
which have many different UNITS as well as different numbering schemes:
feet
tenths-of-feet ["big inches"]
feet-and-inches
cumulative inches
binary inch-fractions
12ths of an inch [architect's rules and 12-pitch graphics rulers]
decimal inches [machinists' rules]
picas
points
agates [14ths of an inch]
links [7.92 inches]
brick masons' tapes [complicated!]
fractional yards
men's, women's, and children's shoe lengths [all require different rulers!]
...totally crazy!
> -----Original Message-----
> From: Joseph B. Reid
>
> This posting is not intended to dispute Dennis's arguments. He
> demonstrates that only a planned and coordinated conversion program can be
> successful. I only want to comment on a misconception that exists on the
American
> measuring tapes that I have seen.
> American style:
> | | | | | | | |
> iii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|ii
> ii|iiii|i
> 60 70 80 90 *500* 10 20 30
> 2 m
>
> European style:
> | | | | | | | |
> iii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|iiii|ii
> ii|iiii|i
> 146 147 148 149 *250* 251 252
> 253
>
> I think that the European style of centimetre numbers at every centimetre
> is easier to read and much less subject to error in reading than the
> American style of millimetre numbers at each centimetre. Beyond 1 m the
> American tape is especialy harder to read. The metre numbers are given in
> small red characters every decimetre along with the 100
> millimetre numbers.
> So, in reading an American tape one has to refer to the preceding
> decimetre to pick up the insignificant red metre number and the bold 100
> millmetre number, and merge these two numbers with the millimetre
> number at the preceding centimetre.
>
