why is the US not Metric

[bsfeechannel]

A few days ago I was considering the use of a piece of nichrome wire I have as a current shunt for a project. Nichrome is not the most solder-friendly material around, but it has a better temperature coefficient than copper, in fact 10 times better. So I decided to investigate its viability. I needed to basically decide its length and calculate the maximum current so that the temperature rise does not change its resistance above a certain tolerance. There are several on-line nichrome wire calculators and the most popular seems to be the Jacobs nichrome calculator. This is a screen shot of it.



The calculator is pretty good and intuitive and, since the Jacobs company is based in the US, it is using primarily imperial units. But then I decided to "metricate" their calculator and this is the result.



Look how uncluttered, clean, coherent and consistent it is now. All the units are metric, instead of a mishmash of different units from the same system (feet and inches, AWG and inches) and from different systems (feet, inches, °F, AWG and cm, °C, volts, ohms and watts).

[CatalinaWOW]

You made an error in your metrification.  The label on the area row says gauge, not area.  So even metric doesn't pay much attention to these foibles.  If it works you go with it.

I will note that the calculator is much cleaner and simpler if you eliminate the metric units.  Not quite as good as metric, but yet another proof that the systems are nearly equal in ease of use.  The standard one would be as clean if you used the single unit of inches for distance, but Jacobs decided to be friendly to all of their customers.   Metric is better, but not so overwhelming as you seem to think it is. 

Think of it this way, use of the existing US system of units requires memorization of perhaps a dozen or so constants, compared to the one touted for metric.  (Will ignore all of the weird units not widely used.  The drams, the furlongs, and all of that long list of traditional units.  We are just talking about the common units used in science and industry.)  The average speaker of a modern language has a vocabulary of at least 5000 words.  Many have a vocabulary much larger - 15000 is common and many even know 35000 or more words.  For an operating system that easily memorizes that quantity of information a difference of a dozen is so far down in the mud that it hardly bears discussion.

[bsfeechannel]

You made an error in your metrification.  The label on the area row says gauge, not area.  So even metric doesn't pay much attention to these foibles.  If it works you go with it.

I did that on purpose.

One crucial data for a wire is its cross sectional area. For a given maximum current density, the cross sectional area is directly proportional to the maximum current. So calculations are straightforward. For a given length, its resistance will be inversely proportional to the area. This means that the maximum power dissipated by the wire will be too directly proportional to the area.

"Gauging" wires by their cross sectional area in mm² is therefore far more advantageous than using the traditional AWG. And that's why in some places people already offer wires and cables dimensioned exclusively in mm², not in any gauge system.

I will note that the calculator is much cleaner and simpler if you eliminate the metric units.

If you eliminate the metric units, the calculator becomes useless, because, alas, the imperial system has no units for voltage, current or resistance, but you can still use HP for power.

[CatalinaWOW]

So using an American term for size is acceptable in metric, as long as you use metric units?  Labeling something incorrectly is a more rational system?   

Your reply has another error, repeated throughout this thread.  While it may be true that the Imperial system has no volts or watts or whatever, as has been repeated over and over, America is metric.  From the 1800s.  So we do use those units.  And have for as long as any other metric country.  America uses what we call the standard system, which has some units that are identical to Imperial units (feet and miles) and some that resemble Imperial units (gallons and others). 

[forrestc]

360 is better because having more factors than 400, so ¹/₃ of a turn or 120 degrees can be expressed without using a fraction.

This allows me to bring up a point that I've been going to make for a while.

In some cases decimal based systems aren't very convenient when translating a measurement to the real world.   It's pretty easy to divide a line segment in half through various methods, including the quite accurate method from classical geometry using a compass and a straight edge.   Dividing it into 10 equal pieces is a fair bit more involved. 

On a circle, dividing a circle into 6 or 12 (or 24) equal pieces is relatively straightforward as well, but 10 is quite a bit more difficult.

It would not surprise me to find that this is the root cause of why inches are generally expressed as whole numbers and fractions where the divisor is a power of two.   And why there are 12 or 24 hours in a day.

[bsfeechannel]

While it may be true that the Imperial system has no volts or watts or whatever

To be fair there were various attempts to define the ohm in terms of imperial or customary units. All of them were abandoned after the  British Association for the Advancement of Science appointed Maxwell and Lord Kelvin to  devise a unit that was of convenient size, part of a complete system for electrical measurements, coherent with the units for energy, stable, reproducible and based on the French metrical system.

  Maxwell and Kelvin saved us. If it weren't for these two we'd be wallowing in the mire of the imperial system.

But I'm starting to see a pattern here. What the UK does with their units, the US does. So I think I found a definite solution to the imperial problem in the US: metricate the UK and the US will follow suit.

as has been repeated over and over, America is metric. From the 1800s.  So we do use those units.  And have for as long as any other metric country.  America uses what we call the standard system, which has some units that are identical to Imperial units (feet and miles) and some that resemble Imperial units (gallons and others).

Unfortunately no one outside the US (and I suspect not many inside) falls for that kind of spin doctoring when reality shows the blatant opposite. You can say that the US is in a slow process of metrication, but it's very far from getting there.

[bsfeechannel]

The Jacobs calculator was cool, but it was only useful for me to calculate the wire dimensions. Below 93 °C the temperature field shows "COLD". That's a bit nonsense. What if I want to build an egg incubator where the temperature must be between 37 and 39 °C? I needed to know the temperature rise above ambient, which shouldn't be more than 1 °C, so that I could assess if the change in resistance would be significant. I then turned my attention to this calculator. Very considerate of them to let us input metric units, but again look at the myriad of units. Meter and millimeter only would be OK.



It'd be also preferable to use °C, which is a derived SI unit, but K, which is a base unit, is alright. (Nothing that adding 273.15 to
°C can't solve). The results are all metric but for one detail: the intruding "Resistance Per Feet": a useless unit for those who come to the site not willing to have their calculations contaminated by imperial.



I can't obviously complain about easycalc or the Jacobs calculator. They're free and I'm thankful they exist. But they show how the use of imperial turns the interface messy.

[CatalinaWOW]

Bsfees, you may not have enough time in the US to understand this, but your last comment demands this:

Dear sweet baby.  Your trials are beyond understanding.  So sad that you have to deal with the world contaminated by non-metric things.

[SilverSolder]

The subject of metrification came up at a party I was at recently...  first time I've ever heard anyone discuss it "live" in the US.  I was just overhearing it, not participating in it. The general attitude was, "Yeah, we all learned it in school, but the implementation project eventually failed."  There was a sense of lament.  These people did feel that Metric was more "modern".  The conversation then moved on to more lament about 30 lost years in space research and the recent Boeing failures.

I got the sense that many Americans know/feel intuitively that several balls have been dropped in recent history and that it's about time to pick them up.

[Zero999]

360 is better because having more factors than 400, so ¹/₃ of a turn or 120 degrees can be expressed without using a fraction.

This allows me to bring up a point that I've been going to make for a while.

In some cases decimal based systems aren't very convenient when translating a measurement to the real world.   It's pretty easy to divide a line segment in half through various methods, including the quite accurate method from classical geometry using a compass and a straight edge.   Dividing it into 10 equal pieces is a fair bit more involved. 

On a circle, dividing a circle into 6 or 12 (or 24) equal pieces is relatively straightforward as well, but 10 is quite a bit more difficult.

It would not surprise me to find that this is the root cause of why inches are generally expressed as whole numbers and fractions where the divisor is a power of two.   And why there are 12 or 24 hours in a day.

Yes, this is probably true. A base 12 numbering system would be better than base 10 in many ways.

The main reason why metric is better than imperial/customary, isn't really to do with base 10 (although that does help a lot), but the fact the whole system was designed from the ground up, with all units being defined from one another.

The SI unit for angles is the radian, which makes calculations much easier, although expressing common angles such as 90° is a pain because π is an irrational number, which generates lots of decimal places. More often than not the angle is expressed as a fraction of π, so you'll see θ = ^π/₂, rather than θ = 15.70796, although if you're going to so that, you might as well use half-turns, but fractions of π are more widespread and well understood.

[KL27x]

but the fact the whole system was designed from the ground up, with all units being defined from one another.

For the next couple weeks, take a notice of how many times this makes any difference in your daily life. You will find it matters none, other than when you're doing some kind of chemistry or physics or having to convert feet of wire to meters. So the advantage to the world is very slim to none. The advantage to American industries and people who already know and use and switch between both as desired, is slim to none. Americans separate the physics and the knowledge from the units. It's the former that is important to understand. The rest is details.

If an American uses imperial (like Captain Sully describing visibility as "3 football fields" on the day of his water landing), I think this is what bothers non-American english speakers. But why do they care?* Were they planning to convert that into Newton-meters? To convert to liters per mm?

Ironically, the non-metric/SI calorie works better with metric idea of "let's make everything related based on distilled water" than the joule.

*The only thing that bothers me with the football field unit is does this include the endzones?  I assume no, but depending on the speaker, you might wonder.

Personally, I think many male Americans know exactly how far they can throw a football in yards (reality plus the extra 20 yards of their imagination). So this makes a good unit for estimation when in the 40-100 yard range. Probably even better are golfers, at estimating visual-range distances. To know what club they would use. In America, we play golf by the yards (and then switch to feet on the green; lol, this surely upsets some of you non-Americans).

Watching football yesterday, I imagined how awful it would be in metric, and it is pretty bad. 4th and decimeters? It looks like he's gonna be a third of a meter shy of the first down?  Nope.

[bsfeechannel]

Your trials are beyond understanding.

Bear with me. I want to show you something. The easycalc nichrome calculator was even worse than the Jacobs calculator. It didn't let me know the temperature below 200 °C. So I landed on this nichrome wire calculator. Despite the name, "Steam Engine", it was created for those who want to build diy e-cigs, a.k.a. vape pens by a Norwegian guy.



It didn't help me either, but I noticed a few things. First, he managed to create two versions of the calculator, one for metric, the default, and another for imperial. Both are equally clean and uncluttered. But in the instructions he writes this.



It sounds almost like "if you are the only nation that that couldn't cope with the transition from the old customary to the modern metric, please click on the appropriate option". It shows that imperial is a whimsical idiosyncrasy of the American people linked with obsolescence.

So it's time to move on. It's time to modernize the units in the US. It's time to be metric and proud of being American.

[KL27x]

Bsfeechannel, you are not being a total idiot in your previous few posts. So I have had no fun from them. But just an FYI regarding your last post. You have no clue about Americans' psychology. Shame don't work. Your example reinforces the fact that other people already know USC and are willing to use it when it benefits them (by say increasing the utility/pophlarity of their app). The complainers? We probably enjoy that, too.

[Cubdriver]

Your trials are beyond understanding.

Bear with me. I want to show you something. The easycalc nichrome calculator was even worse than the Jacobs calculator. It didn't let me know the temperature below 200 °C. So I landed on this nichrome wire calculator. Despite the name, "Steam Engine", it was created for those who want to build diy e-cigs, a.k.a. vape pens by a Norwegian guy.

(Attachment Link)

It didn't help me either, but I noticed a few things. First, he managed to create two versions of the calculator, one for metric, the default, and another for imperial. Both are equally clean and uncluttered. But in the instructions he writes this.

(Attachment Link)

It sounds almost like "if you are the only nation that that couldn't cope with the transition from the old customary to the modern metric, please click on the appropriate option". It shows that imperial is a whimsical idiosyncrasy of the American people linked with obsolescence.

So it's time to move on. It's time to modernize the units in the US. It's time to be metric and proud of being American.

Or, maybe it's helpful clarification for people who are used to inches but don't necessarily refer to them as "imperial" units.  (Yeah, I know - we Americans are stupid, aren't we?)  It shows imperial as an alternate way to refer to measurements in inches.

And I'm quite capable of being a proud American while using either metric or imperial measurements as I deem best for any particular situation.  If you lack the versatility to switch between as needed, well, I'm sorry for you.  For instance, my house is built using material measured in that archaic imperial system - when working on it, I can see no good reason to try to measure things in metric units (when what I'm working with and what I'm working on is measured in inches and feet) because folks in Europe do, or to suit someone on an internet forum.  You still don't seem to grasp that things built in inches and feet will not magically transmogrify into metric.  If I'm working with a sheet of plywood, I prefer to deal with numbers like 48 x 96", or 4 x 8' (what it is sold in here, and the standard sizes used in construction) than 1219.2 x 2438.4mm.  If you prefer the latter, have at it, but measuring in the native units seem much more sensible to me.

-Pat

[CatalinaWOW]

Bfees, if you had spent as much time working on your problem as you did trying to find pure metric sources you would have found that the reason most calculators don't work below 200 C is the paucity of data below that temperature range.  You might have discovered that differences between material specs really do matter.  And discovered that the reason for the paucity of data is that other materials are better suited to use at lower temperatures.  But your situation might be special - nichrome might really be the right answer for your application.  So I strongly encourage you to spend your time searching for source level data on the nichrome you propose using rather than finding a friendly calculator or trying to convince me and other Americans how much better our lives would be if we got busy and shamed our compatriots into switching completely and irrevocably to metric. 

Your continued rants on this subject are as endearing as continued American rants on how wonderful our political system is, and how everyone on earth should adopt it.  You can see how well that is working for us.

[KL27x]

Also, the problem with "pure metric," is for when you are done doing the calculations. When you are building your thingamabob, you might have more than one gauge of wires at your work. It's easier to "Hey Bob, we're running low on the 14 gauge. Can you order some more?" Vs saying "hand me the 0.01787mm^2 wire." So why not use both?

As a design engineer, you might often do things just once. Then wash your hands of it. But unless you stink at your job, someone else will often repeat your design many times. So should you just deal with it once? Or to make your life one gram easier, you want the rest of the world to use only metric units wherever possible, when they do this repeatedly, over and over.

99% of engineers don't do anything new. Just slight variations for w/e app. Bridging the gaps when combining things in new ways. For the most of us, we don't invent shit. We just handle the details by understanding what is already known, and having some idea of the issues in the actual execution. This almost always involves writing things down and looking this up.

[bsfeechannel]

You have no clue about Americans' psychology. Shame don't work.

Well, at least they used to feel shame in the past.

Obituary of Fred M. Thrower, former president of WPIX TV.
Innovations for which he will be remembered include the Christmas Eve ''Yule Log'' telecast, WPIX multi award-winning editorials and the impact of his single slide that said ''Shame'' that appeared on the screen for several hours after the death of Robert Kennedy.

Since it seems that shame is officially dead and we live in an era of shamelessness, I'll have to think about something else to encourage people to go metric.

[SilverSolder]

[...]  I'll have to think about something else to encourage people to go metric.

Sex? 

"It is scientifically proven that people that understand Metric are more attractive to the opposite sex!"

"15cm or only 6 inches? - No contest!"

etc.   

[paulca]

Has anyone mentioned that the US units ARE defined in metric and calibrated against metric these days?

[Cubdriver]

Has anyone mentioned that the US units ARE defined in metric and calibrated against metric these days?

Probably not more than a dozen or so times...

-Pat

[schmitt trigger]

I love a sunburnt country,
A land of sweeping plains,
Of ragged mountain ranges,
Of droughts and flooding rains.
I love her far horizons,
I love her jewel-sea,
Her beauty and her terror
The wide brown land for me!   

This is such a beautiful poem.
Between it and the song "Land Down Under", have made visiting Australia one of the objects in my bucket list.

Right now, all I can do is enjoy a Vegemite sandwich.

[bsfeechannel]

[...]  I'll have to think about something else to encourage people to go metric.

Sex? 

"It is scientifically proven that people that understand Metric are more attractive to the opposite sex!"

"15cm or only 6 inches? - No contest!"

etc.   

Nah. They'll complain that they won't be able to understand this Mae West's memorable quote:



No. It must be something that appeals to what they are crazy for, something they won't resist or raise objections to.

[mariush]

Also, the problem with "pure metric," is for when you are done doing the calculations. When you are building your thingamabob, you might have more than one gauge of wires at your work. It's easier to "Hey Bob, we're running low on the 14 gauge. Can you order some more?" Vs saying "hand me the 0.01787mm^2 wire." So why not use both?

How is it easier to say 14 gauge... do you keep in your head all the diameters and areas for all gauges?

For example AWG 14 is 0.0641 in or 1.628mm diameter,  or 2.08 mm2  ... you could just round it and ask for 2mm2 wire or 2.1mm2 wire

0.01787 mm^2 area would correspond to something between AWG 34 and AWG 35...  0.00561 in , 0.143mm diameter and  0.0160mm2  ... just round it up and ask for 0.15mm diameter  or 0.02mm2 area ?

Instead of 40 gauges and 4 different 0 gauges, you could have 0.01mm .. 1mm in 0.01 steps or 0.025mm steps , 1mm..2mm in 0.1 steps, 2mm+ in 0.25mm steps ... not that hard.

Would be easier to just say directly the area or diameter... or maybe use another parameter like resistance per meter where actual thickness is less relevant (ex use aluminum wires or steel wires vs copper wires)

[paulca]

No. It must be something that appeals to what they are crazy for, something they won't resist or raise objections to.

Metric has oil.
Metric are FREEDOM units!

[GeorgeOfTheJungle]

But democracy is delivered in US customary units.