I work in a toxicology lab, and everything uses SI–chemicals, glassware, instruments, etc. The only thing I can think of that isn’t primarily in SI is paper for obvious reasons.
And don’t forget that the US Customary System of Measurements is not the Imperial System of Measurements used by the British Empire after the early 19th century, and neither is the old “English” system that the Imperial system superseded.
A comparison between the US and Imperial systems.
As a Canadian, I have to deal with ALL of these, except possibly the old English measurements. And it pisses me off.
Canada botched its conversion to SI measure by never finishing it, and many fields including publishing, residential house design, and cooking still tend to use Imperial measure. Then there are the differences between US and Imperial measure: when a Canadian ad mentions a car’s fuel usage in “miles per gallon”, is that “miles per US gallon” or “miles per Imperial gallon”? Especially since we buy fuel in litres and measure fuel usage in litres per 100 kilometres? IMHO half this stuff is either comparisons to US models, or sops to the older generations who still stubbornly cling to the old measures.
When I was investigating house drawings, I was dragged kicking and screaming backwards from the SI world. I would do my heat and volume calculations in joules and kelvins and millimetres, and convert to BTU/hour and degrees Fahrenheit and cubic feet at the end… especially since our regulations are in SI but our small-scalle typical-handyman construction still tends to take place in feet and inches.
Not that I was ever far from it; Canada may be the only country outside the US that still dimensions all its paper in inches as well. So even in ly old job, we usually designed our manuals and publications in inches, often to fit US “letter-size” paper: 8.5 inches x 11 inches.
I know that feel bro!
That would be my shipmates and I studying in Navy Nuclear Power School ages ago. We did everything in English units, including the thermodynamics, chemistry, materials science, reactor theory/nuclear physics. I suppose some of our work was in SI units, but the vast majority was in BTUs, Horsepower, and even lb-m and lb-f.
I remember peppering our equations with the “proportionality constant” which was the cheater constant that allowed us to work in lb-f and lb-m at the same time.
I recall that all of the charts and graphs were in English units (e.g. steam tables), so maybe that had something to do with it. I wonder if they have gone metric in recent years.
I work in electromagnetics, and I’ve never used them with English units. When I was first taking physics as an undergrad, we used cgs (centimeter,gram,second), and called it Gaussian units (but I’ve since learned there are more than one set called “Gaussian”). When I began taking electromagnetics in electrical engineering, we used mks (meter,kilogram,second), and different Maxwell’s equations (the fundamental equations of electromagnetics). When I took graduate-level physics, the units were mks, but the equations were more like the ones we used in cgs. Somewhere in there, we used both exp(+j omega t) and exp(-j omega t) time conventions (i.e. whether lossy material will have a positive or negative imaginary part). If you’re counting, that’s three sets of equations/units spread over two time conventions, and none of them were in English units.
At work, we use the electrical engineering equations and mks units, which maybe are the SI units, I’m not really sure. I always use meters in any codes I write or work with, immediately converting any inputs in other units. When I have to interface with manufacturing, they usually work in inches or maybe feet, so I know those conversion factors. I still run into both time conventions, and frankly, that’s more confusing than converting between inches and meters.
It may be SI, but for some reason American clinical labs insist on using SI-but-different-from-everyone-else’s-units. For example, US measures glucose (among others) in mg/dl. Everyone else uses mmol/L.
Dear god, why? If you’re going SI, why not go with the same units that the rest of the world has agreed on?
Same, but I used lbm last month at work. Gotta love good ol’ Crane TP-410.
I work in the (American) auto industry. We work pretty much exclusively in SI units. Well, aside from horsepower and torque; dimensionally its all in SI. Fasteners are all specified with SI dimensions,etc. We might conversationally talk about 6.5" speakers, but we’re really dealing with 165mm speakers.
The US automobile industry uses SI for all its design work. Every part on the car has its dimensions spelled out in millimeters – even big parts, where centimeters or even meters might seem more logical.
I’m not sure this complaint makes sense. What does it mean to dimension in a unit? If you’re talking about round numbers, then US letter size qualifies, being 11x8.5". But A4 paper does not, being approximately 297.301 x 210.224 mm. Well, they do actually round it down to 297x210, but even so these aren’t nice-looking numbers, given that they derive from multiples of sqrt(2).
The only thing even semi-metric about the A-series paper is the area, which for A4 is 1/16 m^2. Which itself looks quaintly Imperial, what with the power-of-2 fraction instead of a power of 10.
My understanding is that the metric system is used in architecture in the same way: millimeters for everything, and unlabeled (except in the legend). Seems like it has lots of advantages, though there’s nothing really specific to the metric system there (you could do the same with inches).
Civil engineer. Hey, give us time. Of course, for the rest of time, we’d be forced to figure out how wide the sidewalks will be if we widen the road from 10 to 12 m, given a 60 foot right-of-way.
US doper here, and an engineer (chemical):
I graduated college in 2004. All the way through college, the science professors made us use SI (it is a better system, and internationally recognized.)
The engineering professors all made us use English units ("yeah, we know SI is better, but industry in the US still uses English units, and it’s not great, but that’s the way it is.)
So I got through a chemical engineering degree using (about half the time) grams and joules, the other half using lbs (mass) and BTU.
And yep, the formula work the same either way, except there will be a “conversion” constant usually on the English unit formulas.
Having been in the chemical industry for nearly 8 years now, yeah. Our manufacturing departments use pounds. Our QC/Analytical/R&D departments use grams and kilograms.
Our smaller “shop” customers usually still use pounds.
But we sell into Canada as well, and they mostly use kg. Even the smaller shops.
So I jump between units every day. I wish we’d all use SI, because it is more intuitive, but institutional inertia is strong.
When I was in architecture school, they told us that buildings would be dimensioned on a 100-mm ‘module’: that a basic grid of locations at multiples of 100 millimetres would be defined, and things would be referenced to it. Plywood would be 1200 x 2400 mm, studs would be on 400- or 600-mm centres, etc.
But.
That was thirty years ago. Small-scale residential construction continues in feet and inches. Plywood remains 4 feet x 8 feet (1219 mm x 2438 mm). Studs remain on 16-inch or 24-inch (406 mm or 610 mm) centres.
I’ve seen plans for larger constructions dimensioned in metric; for instance, this railway underpass (Figure 12 on the fourth page of the linked PDF) has clearances and elevations dimensioned in millimetres, and appears to use metric throughout, with a few Imperial measurements added for reference. (For railways which use miles and miles per hour internally for their own operations…)
In reality the advantages of SI are over rated for most purposes. When I need to know the distance from here to Mars in millimeters, then just being able to shift decimal places will be really handy, but for the most part English units are perfectly suited for the dimensions they are intended. Calculators make converting units trivial and I never have had to convert units on the fly.
The one exception is an oven I have at work that works in Fahrenheit, and that drives me batty.
The units being related by powers of 10 is handy, but you’re right that it’s ultimately not that big a deal. What is a big deal, though, is that everything uses the same units. The unit of force is equal to the unit of mass times the unit of length divided by the square of the unit of time. The unit of energy is equal to the unit of force times the unit of distance. The unit of rotational speed is one over the unit of time. All of these are things that do show up regularly in real-world calculations.
Here’s a pop quiz: Suppose I have a fish tank that’s 2 feet long by 1 foot wide by 1 1/2 feet high. How many gallons does will it hold? Explain how you got your answer.
May I assume the tank is a rectangular prism? Inside or outside dimensions? If outside, how thick is the glass? How far below the top edge is the water level? How much gravel is there? How big is the tank heater? Rocks? Also, what country do you live in?
I joke, but the point is that a simple multiply by 7.48 (assuming US) is an infinitesimal fraction of the entire calculation. The hard parts are the same in SI or Imperial.
This is true. When I took a job at the Ashland Chemical research headquarters in the70’s, I was appalled to find their resin and plastic group working in pounds and Fahrenheit. I quickly adjusted. I see little utility in water being spg 1.0 when usually you are needing to pounds per gallon or specific gravity.
It’s no different than the common use of kilograms for weight.
American biologist here. All SI, all the time.