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Common mistakes when using the metric system

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Re: Common mistakes when using the metric system

#21

Post by boxed »

ikari_pl wrote: post #14

I was surprised to see "L" as the "only correct" (though as minor mistake) abbreviation for a liter, being certain "l" or "ℓ" is the way to go, as that's how I was taught so far. Turns out that SI actually allows both "l" and "L", but I would only ever use the uppercase if it's a sans-serif font in a non-prefixed unit ("L" as opposed to "ml"). I've never seen any can or bottle using "mL" or "cL". Some of the examples…

I live in metric land (Sweden), and I have never seen "gr." for grams and honestly I would probably take a while to understand what it meant.

Re: Common mistakes when using the metric system

#23

Post by unwind »

newaccount74 wrote: post #10
ndsipa_pomu wrote: post #2

So, when using the kelvin temperature scale, it's lower case when using "kelvin", but uppercase when using the abbreviation "K"? That annoys me as kelvin is a name and even my phone wants to capitalise it.

I disagree with that rule. I get that people spell liter, gram, meter in lower case, but units based on names of historic persons like Volt, Ampere, Coulomb, Pascal and Kelvin deserve to be capitalized.

The unit symbols for those units (A, C, P and K) are capitalized, but the units when spelled out (ampere, coulomb, pascal and kelvin) are not, just like the spelled out forms of liter, gram and meter.

Re: Common mistakes when using the metric system

#24

Post by boxed »

atoav wrote: post #13
readthenotes1 wrote: post #8

Earlier quoted context omitted.

60 watts , later 20 kW. I don't know, but it seems to me that if they wanted to be scientific they wouldn't be seemingly arbitrary in the capitalization rules

I had structural engineering and electronics in school and especially when you get compound units like Nm (newton meters) not wondering if the N is a newton or the SI-prefix nano is not nothing. In the end the reason for the weird capitalization is just to avoid situations where that ambiguity will occur.

I remember me and a friend asking our physics teacher if it wasn't a problem that tera (T) and tesla (T) were the same symbol. He looked at us, paused a bit, then explained how absolutely enormous a terra tesla would be, and thus why that isn't actually an issue :P

Re: Common mistakes when using the metric system

#25

Post by boxed »

newaccount74 wrote: post #10
ndsipa_pomu wrote: post #2

So, when using the kelvin temperature scale, it's lower case when using "kelvin", but uppercase when using the abbreviation "K"? That annoys me as kelvin is a name and even my phone wants to capitalise it.

I disagree with that rule. I get that people spell liter, gram, meter in lower case, but units based on names of historic persons like Volt, Ampere, Coulomb, Pascal and Kelvin deserve to be capitalized.

Isn't it more logical that Volt was the person and volt is the unit named after the person? To me that makes perfect sense.

Re: Common mistakes when using the metric system

#26

Post by shiroiushi »

newaccount74 wrote: post #10
ndsipa_pomu wrote: post #2

So, when using the kelvin temperature scale, it's lower case when using "kelvin", but uppercase when using the abbreviation "K"? That annoys me as kelvin is a name and even my phone wants to capitalise it.

I disagree with that rule. I get that people spell liter, gram, meter in lower case, but units based on names of historic persons like Volt, Ampere, Coulomb, Pascal and Kelvin deserve to be capitalized.

No they don't. When you're actually referring to those people, then yes, you would capitalize them. When you use units named after them, you don't.

Re: Common mistakes when using the metric system

#28

Post by ulbu »

boxed wrote: post #21
ikari_pl wrote: post #14

I was surprised to see "L" as the "only correct" (though as minor mistake) abbreviation for a liter, being certain "l" or "ℓ" is the way to go, as that's how I was taught so far. Turns out that SI actually allows both "l" and "L", but I would only ever use the uppercase if it's a sans-serif font in a non-prefixed unit ("L" as opposed to "ml"). I've never seen any can or bottle using "mL" or "cL". Some of the examples…

I live in metric land (Sweden), and I have never seen "gr." for grams and honestly I would probably take a while to understand what it meant.

yea, reads like "grains"

Re: Common mistakes when using the metric system

#29

Post by ulbu »

setopt wrote: post #17
tommiegannert wrote: post #9

> 81 uL of catalyst -> 81 μL of catalyst Oh, interesting. NIST recommends "L": https://www.nist.gov/pml/special-publication-811/nist-guide-...

Note: The official SI unit “liter” was written “l” until a couple of decades ago, when they changed it to “L” due to frequent legibility issues (l/I/1). Some old texts use the old convention.

they did not change it, they added it as an acceptable form
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