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One of the problems with various HPs with labeled key unit conversions is that they are based on US units which makes some of them useless to users in countries not using US units.
For example, many HPs have keyed litre/gallon conversions but the US Gallon is used. Here in the UK, our gallon is about 104/125 of a US Gallon. There are other less-used units too.
The big machines like the 48 and 49 series offer the alternatives but the simpler machines with labeled key conversions don't.
So the proposed solution is for Units Localisation where you set your locale and the appropriate units are used. This is something TI have already done and would be a really useful feature in future HPs. At the same time, the locale can be used for setting default date format and radix.
If anyone who has the necessary power is reading this, I hope you understand the need for this proposal and consider it worthwhile!
Thank you very much.
Mark
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hello
Quote:
For example, many HPs have keyed litre/gallon conversions but the US Gallon is used. Here in the UK, our gallon is about 104/125 of a US Gallon. There are other less-used units too.
But, being part of the EU, the UK is supposed to switch to a real unit system, so you don't have to convert anymore... while in the US, they are still stuck in the dark ages (which strangely they never lived through due to the fact that the US was not yet discovered)... and need the conversion...
anyhow, what other conversions do you want? Stones to KG? Chain to Furlong? I hope that you don't need an implementation of the old english monetary system!
:-)
regards, cyrille
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say what you want about US units, they've managed to put men on the moon :-)
anyhow, I'm in favour of the Units Localisation proposed.
hpnut in Malaysia (we have SI units)
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Wasn't there a time the NASA lost a sattelite because off poor unit conversions? :-)
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:-D That was on Mars -- and that's a completely different story than the Moon! ;) Other laws rule -- presumably they'd use local US-Martian units there...
Ceterum censeo: Put all these unit conversions into a menu. For the next century or so (i.e. until the USA adopt SI -- Liberia and Myanmar will do earlier I assume) the user may customize this menu, or may reassign this space to contain something useful.
Edited: 5 Aug 2008, 1:41 a.m.
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...and managed to crash a few hundered million USD worth of spacecraft on the Mars as they screwed up the conversion...
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Quote:
in the US, they are still stuck in the dark ages ... and need the conversion...
regards, cyrille
Actually, Cyrille, the U.S. has been "stuck" in between metric and English units for a long time. During WWII, for instance, the Army used metric for artillery, both gun size and range calculations, while the Navy used English (now called US Customary) for both.
Uh, except the Army used decimal inches for small arms caliber and the Navy used 20mm and 40mm anti-aircraft guns...
Today, we buy soda in 2 liter bottles, but 12 ounce cans. Our automobile engines come in liter displacement, but are rated in horsepower and foot-pounds. Our tires are metric sized, but we inflate them to pounds per square inch pressure. Should I go on?
I will. We still (mostly) survey in feet and acres, but we have two different feet, the "US Survey Foot" and the "International Foot", caused by a change in the definition of the meter!!
So we hold on to our traditional units, but add metric units as well. Many Europeans are bi-lingual. We Americans are bi-unital, to coin a phrase.
Martin
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psi, I recall the first time I had to inflate a tire in France, the machine had several scales, one in atmospheres which I used.
The other 2 used units I had never heard of. Still in the dark ages. I think we have to educate the kids, and let the old ones die off, Sam
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This site has a lot of information on the metric system in the US, including what the law says: www.metric.org
As a french person living in the US, there's only one unit conversion I'm having trouble with: euros to dollars. Keep changing all the time, and not in the right direction :-)
-- alain.
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Quote:
As a french person living in the US, there's only one unit conversion I'm having trouble with: euros to dollars. Keep changing all the time, and not in the right direction :-)
Pourquoi? = Why? ;)
Salutations, Walter
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I partially blame pocket calculators for us being "bi-unital" (thanks for that!). In the late 60's and early 70's a good piece of the NY State science curriculum was spent teaching junior and senior high school kids the metric system. The whole country was suppose to convert to this in the future and we were to be ready, congress even passed the Metric Conversion Act of 1975. Given the increasing prevalence of English the rest of the world was forced to deal with at the time, I thought that this was a fair trade.
However we really never did follow through on our end of the bargain. I believe that the advent of low cost pocket calculators was partially to blame since it made converting between units so easy. Part of my calculator collection is dedicated to metric conversion calculators from 70's somewhat supporting this notion.
-Katie
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Quote: I believe that the advent of low cost pocket calculators was partially to blame since it made converting between units so easy
Partially, yes. But the public has a huge inertia, and not just here. Back in France, my grand-parents were always talking in "ancien-francs", meaning the francs before the devaluation of the 50's. Understandable for them. For my generation, we should have switched, but we were still using that old unit in places where it was convenient. At the farmers market, the "livre" (french name for a pound) is still commonly used, even though on the scale people weigh it as 0.5 kg.
Units we use are associated with a mental representation of what it is. I'm now used to Fahrenheit scale because I know what 70 or 32 feels like, not because I have a calculator to convert to Celsius all the time.
My point is: converting unit as an engineer is easy. You tell me what unit you want the result in, what is the formula to convert, I'll program it, done. In everyday life, we tend to choose the unit that will best communicate what we have in mind. Hence a huge inertia.
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Quote:
Our tires are metric sized, but we inflate them to pounds per square inch pressure.
Tire size 185/75R14
width is 185 mm, diameter is 14 inches
You'll find 760 kPs and 110 psi on it
Best of both worlds, hehe ;)
Edited: 6 Aug 2008, 1:22 a.m.
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Quote:
You'll find 760 kPs and 110 psi on it
I hope you find k Pa on it ;)
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Quote:
I hope you find kPa on it ;)
I would also like to think that pressure was measured in kPa. Maybe they got it confused with 760 kilometers per second, the speed at which you can drive this awesome tire ;-)
Edited: 6 Aug 2008, 3:32 a.m.
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Hmmh, presumably this picture was drawn in the USA, wasn't it? Anyway, the SI-unit for pressure is 1 N/m^2 = 1 Pa, as you may read also here.
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I can't speak for the Brits, but here in the U.S. we could use a Smoots to Meters conversion.
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Hi Cyrille,
Yes, you are right about the SI units change-over so by law, imperial units cannot be used (although I think there might be some small exceptions).
However, there are two additional points I want to make.
Whilst retail has gone SI, social is still very much stuck with imperial. Everyone knows their own weight by Stone. People know their cars by mpg or the size of the tank in imperial gallons. A need for conversion with these units still exists here.
Also, old machinery, especially certain levels of industrial machines will have all their specifications quoted in imperial. When it comes to maintaining these devices or making sure you are using them within spec, you have to convert from old to new. Trailer loadings will be quoted in CWT for example. Fuel specs in gallons. Whilst all new devices will be in SI, old devices will be in imperial. The need exists here too.
A while back, I got caught out by a conversion when by mistake, I used US gallons instead of UK gallons, found myself in a big argument over it, found out I was wrong and then found that this difference exists.
Yes, I would like to see Stones and CWT on all unit conversions. When I found these in the HP19B II, I couldn't help wonder why they were taken out in the later machines. These units are very useful.
So whilst SI rules for the future, Imperial has a large legacy which isn't going to go away for a long long time and supporting that legacy means keeping imperial units available and making sure the right ones are used where local differences exist. Hence the proposal.
Thanks for listening and I hope I explained that clearly! :)
Mark
Quote:
hello
But, being part of the EU, the UK is supposed to switch to a real unit system, so you don't have to convert anymore... while in the US, they are still stuck in the dark ages (which strangely they never lived through due to the fact that the US was not yet discovered)... and need the conversion...
anyhow, what other conversions do you want? Stones to KG? Chain to Furlong? I hope that you don't need an implementation of the old english monetary system!
:-)
regards, cyrille
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Localisation is the wrong answer. A calculator sold in the UK should get the same results as a calculator sold in the US, when given the same problem. In a case like that, the calculator should have both units, with different names.
For gallon, it should have the U.S. liquid gallon (3.785411784 l), the U.S. dry gallon (4.40488377086 l), and the imperial gallon (4.54609 l).
If you really were going to have a calculator have conversions on a key, with different values in different parts of the world, then the key legend should explicitly indicate which unit is used, rather than just "gallon".
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Hi, Eric --
Quote:
Localisation is the wrong answer. A calculator sold in the UK should get the same results as a calculator sold in the US, when given the same problem. In a case like that, the calculator should have both units, with different names.
...
If you really were going to have a calculator have conversions on a key, with different values in different parts of the world, then the key legend should explicitly indicate which unit is used, rather than just "gallon".
I would agree.
Quote:
For gallon, it should have the U.S. liquid gallon (3.785411784 l), the U.S. dry gallon (4.40488377086 l), and the imperial gallon (4.54609 l).
The unit catalogue and conversions (direct and compound) offered by the HP-28 are excellent, although it does not permit attachment of units to numbers. The HP-28C/S is worth having on that basis alone.
The HP-28C provides the US liquid gallon ("gal"; 0.003785411784 m^3), the Canadian gallon ("galC"; 0.00454609 m^3), and the Imperial gallon ("galUK"; 0.004546092 m^3), as well as multiple units of feet and ounces (fluid and weight).
-- KS
Edited: 5 Aug 2008, 2:34 a.m. after one or more responses were posted
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Let's point out that
95% of mankind don't have a problem here.
Edited: 5 Aug 2008, 1:52 a.m.
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Quote:
Hi, Eric --
The unit catalogue and conversions (direct and compound) offered by the HP-28 are excellent, although it does not permit attachment of units to numbers. The HP-28C/S is worth having on that basis alone.
The HP-28C provides the US liquid gallon ("gal"; 0.003785411784 m^3), the Canadian gallon ("galC"; 0.00454609 m^3), and the Imperial gallon ("galUK"; 0.004546092 m^3), as well as multiple units of feet and ounces (fluid and weight).
-- KS
the HP 48G also has the US, Canadian & Imperial gallon units.
come to think of it, these English speaking countries don't count in the same way :-)
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Quote:
the HP 48G also has the US, Canadian & Imperial gallon units.
I didn't say that only the HP-28C/S offers these, but the unit catalogue of these models provide the full name of the unit with its value and dimensions in SI -- a good electronic reference to have.
-- KS
Edited: 6 Aug 2008, 2:12 a.m.
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Another problem with labelled units conversion (eg on the 35s) is that they mix SI units and cgs units:
kg km l -- SI units (multiples of 1000)
cm -- cgs unit (multiples of 100)
The length conversion is to cm (cgs unit) where it should be either to m or mm (SI units).
I guess a general solution would be to allow the conversion buttons to be associated (through a setup menu or somesuch) with any pair of dimensionally-equivalent units. The keyboard decal would then simply indicate the default.
Neal.
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