METRIC ! 52

[ceesjan]

Don't you think it's time for engineers all over the world to use the same system?? Ofcourse this must be the metric system!

c-j

 

[flamby]

The best thing I like about metric is that 1 cubic meter of water weighs 1000 Kg! And considering value of acceleration due to gravity is go close to 10 (9.81 actual) it makes it 10 KN. Its like magic!!

 

[owg]

According to this site:

http://www.ex.ac.uk/cimt/dictunit/dictunit.htm#standards

the following rules apply to the use of numbers in the SI System.

"To make numbers easier to read they may be divided into groups of 3 separated by spaces (or half-spaces) but NOT commas.
The SI preferred way of showing a decimal fraction is to use a comma (123,456) to separate the whole number from its fractional part. The practice of using a point, as is common in English-speaking countries, is acceptable providing only that the point is placed ON the line of the bottom edge of the numbers (123.456) and NOT in the middle."

There seems to be no pre-set way of setting up Excel to use this system, although Format, Custom, can handle it. Do SI fans use this system or just ignore it. HAZOP at

http://www.curryhydrocarbons.ca

 

[SERVOCAM]

How many companies do you know that did this when they converted to metric? They took their english dims, say there was a part that was 3.75 inche long, it is now 95.25mm.

I am getting use to working in metric in the Motion Control world. The problem is that every customer seems to work in different units. in, ft, mm, cm, m..... one mfg list specs in kg-m^2, then next in kg-cm^2, the english in lb-in-sec^2 and oz-in-sec^2.....

This is why all of us need that 500 page book full of unit conversion tables.

In Motion Control, when some one asks for a 36" stage, they get 900mm (35.43 inches). I see this a lot too: Give me 300mm of travel and English mounting holes.

I'm sure the state patrol would love it, changing all the signs to metric. All of us going 100 mph when we are suppose to be going 65 mph (100 km/hr).

Cameron Anderson - Sales & Applications Engineer
Aerotech, Inc. -

http://www.aerotech.com

"Dedicated to the Science of Motion"

 

[Escher]

owg
With regard to road signs, I was in Ireland the other month and many distance signs are Metric and some still imperial. The Metric are white on green, Imperial black on white.

No problem in the small Toyota hire car I was driving. All the display was LED... speedometer, odometer, trip computer....and there was a handy button which allowed you to switch backwards & forwards; metric or imperial as you feel inclined. Of course you had to remember the speed limit (posted in metric) so Metric was my preferred option especially in speed zoned areas.

While I had no problem driving cars with imperial speedos for about 8 years after we converted (Australia), it seems like a good marketing ploy for vehicles that may be taken to different countries.

Another innovation (to me) was a big transparent sign on the windscreen reminding you on which side of the road you should be driving. Of course the steering wheel was securely mounted on the right.

 

[RDK]

OWG

You can change the settings for number format for all windows applications.

Contror panel then regional settings and put in the number, date and currency formats that you need.

Rick Kitson MBA P.Eng

Construction Project Management
From conception to completion

http://www.kitsonengineering.com

 

[PBroad]

Living Canada I have long accepted US or Imperial gallons which ever the design called for. But if US does not use Imperial what does it use, and by the way Enland uses (mostly) metric not "English".

The one I find hardest in US is why report metal production (such as copper) in million pounds/yr. Why not tons. I see there is now a move to update this to millions of kg/yr again why not tonnes.

Just for one last confusion. In Europe they don't use decimal points but a decimal comma. So next time you see 1 234,56" it might not be a typo, comme il faut.

 

[MASSEY]

One sure to convert the unconverted from 'english' to metric units is to have them take 'Dynamics' class in college.

After a few attempts trying to calculate accelerations using 'slugs', almost everyone converts original information to metric units. Then if the answer is required in 'english' units, it is converted from the 'metric' answer obtained working the problem in usable units.

Slugs is a good name as it is indicative of engineers who are too stubborn or 'sluggish' to use the only international system of units that makes sense to use.

 

[owg]

RDK, thanks for the tip on using Control Panel. I guess I was not thinking outside of the box. HAZOP at

http://www.curryhydrocarbons.ca

 

[uppili11]

As a supplier to many automotive industries some times we come across funny drawings.One major US auto company the drawings are in metrics and suddenly we get another print which are all in inches one has to look for clerks table to understand what it means.the biggest problem is for the us companies only because most of the standard parts for the components all over the world are in metric system and it is impossible for the US companies to get some standard ittem which is non metric.for example the standard shaftat could be 8mm diameter and the other mating parts you can easily get to match that.This is not the case otherwise and one has to ultimately turn to metric system since majority of the supplies to US are from countries like china are metric based.

 

[rob1283]

As Escher mentioned, here in Ireland the signage is in kilometers(this crossover has been going on for the past number of years and is not yet fully complete). However, the speed limit signs are in miles per hour and continue to be this way. I think, Escher, you had a leisurely drive around the country if you believed the speed limit signs were in metric.

Another example, myself and a friend of mine, who is from South Africa entered a 10km road race about two years ago in Limerick. All the adverts and pre-race publicity talked of a 10k road race. When he got to the '5' marker, he thought his performance on the day was very poor, so he started to up the pace. Soon afterwards, he saw the finishing line.....yes, the markers were in miles!!!

Yes, it's a funny old world...

 

[rob1283]

As Escher mentioned, here in Ireland the signage is in kilometers(this crossover has been going on for the past number of years and is not yet fully complete). However, the speed limit signs are in miles per hour and continue to be this way. I think, Escher, you had a leisurely drive around the country if you believed the speed limit signs were in metric.

Another example, myself and a friend of mine, who is from South Africa(metric system is in place there on infrastructure) entered a 10km road race about two years ago in Limerick. All the adverts and pre-race publicity talked of a 10k road race. When he got to the '5' marker, he thought his performance on the day was very poor, so he started to up the pace. Soon afterwards, he saw the finishing line.....yes, the markers were in miles!!!

Yes, it's a funny old world...

 

[Technochicken]

Well, for those of us in Canada (and anywhere else...) that have to live with both US and metric systems and may have trouble with conversions, here's a little tool to help out.

http://www.onlineconversion.com

 

[GSC]

Let me add my favourite to this interesting discussion:

Measure in micrometres, mark with chalk, cut with an axe

ps: as you see I favor metric... (using 1/16th of an inch is killing me!!!)

GSC

 

[kmacsys]

I agree with many that believe that the metric system is simply easier to navigate (calculating volumes of concrete, MxMxM thickness easily gives you a volume, I worked in South Africa as an engineer and it was much easier than in the USA. I do concur with the mindset of Americans with their sq in, sq ft, acres, cubic yards etc. as a way of "mentally knowing the size, volume, etc.", this will not go away anytime soon, unless the US gov't, as in other countries merely insist legally the use of metric. I don't see this happening soon.

 

[jmw]

For some time fluid density meter manufacturers used the SI convention to express accuracy. e.g. +/-0.1kg/m3.
Then came the day the coriolis mass meter manufacturers decided to target the density measurement market. As mainly american manufacturers they decided to quote not lbs/ft3 as they usually did but to use g/cc. e.g. +/-0.0005g/cc. For some reason end users seemed to think +/-0.0005g/cc was more accurate than +/-0.1kg/m3 so then the density meter manuafacturers had to follow suite and now quote +/-0.0001g/cc except for fiscal metering where they may still quote kg/m3.
And who said its easy enough to convert between one system and another? what happened to the Hubble telescope?

 

[MASSEY]

I for one do not believe the hubble or mars probe errors are due to conversion errors.

I an not generally given to conspiracy theories, but I do not buy into scientists and engineers making conversion errors or forgeting to convert or whatever.

 

[jmw]

Conspiracy theories? I don't believe i made any mention fo such. I was talking about being creative/imaginative with the figures ("lies, damned lies and statistics" sound familiar to you?). You are probably right about Hubble though, and though the Hubble news centre doesn't exactly give anything away, they don't assign a cause to the problem. According to other sources they finally assigned the blame to an incorrectly assembled test instrument. I just recall the original news coverage in the UK suggesting (mischieviouly?) that the cause was conversion factors.
Of course i have as much or as little difficulty believing a scientist or an engineer can miss-assemble a test instrument so it is only 1/50thou off as i have about them making conversion errors. If i "miss-assembled a test instrument you can bet if could bet it a meter or more off.
I have no reason to doubt the official story but it wouldn't surprise me if at some time in some similar situation some one hasn't invented some less embaraasing story to tell the public than the real truth.
But this is about engineers and scientists not making mistakes...i am reminded of the old carpenters adage... measure twice and cut once. i.e. we are all fallable and we are most fallable when we decide we are infallable and measure only once. Hubble is the proof of the ability of engineers to err and it really doesn't make much difference whether it is because they can't convert or they can't follow the assembly instructions properly. (And who reads the instructions these days...? and there is another problem... with assembly instructions required in multiple languages today, the actual content has decreased to a meaningles legal minimum). The main point is that if we have to make conversions we will make mistakes. It is an unnecessary step, or at least, one which can be eliminated while i doubt we can eliminate instruction manuals or make them readable and helpful. If conversions have to be made i don't care who it is, sooner or later human beings will find a way to foul up. A lot of engineering today is about is making things "idiot-proof", the newer your computer the less decisions it allows you to make..."plug and play", "straight from the box"... and so on progressively eliminating any possible areas where people can mess up. And if you think engineers can't mess up a conversion then you won't prove it by my colleagues and I. Take the example i gave, we were caught out in one of the factors we quote because we got the too few noughts (zeros) in the specification; not one engineer, but several, the guy who wrote it up and the guys who checked him.

 

[owg]

If you don't believe Hubble was an SI screw up here is a link to a well documented one.

http://www.airdisaster.com/cgi_bin/view_details.cgi?date=07231983&reg=C-GAUN&airline=Air+Canada

Working in two languages and two measuring systems we managed to put only one quarter the necessary fuel into a 747 which had to crash land on an disused runway/racetrack when they ran out of fuel. HAZOP at

http://www.curryhydrocarbons.ca

 

[owg]

Correction, it was a Boeing 767. HAZOP at

http://www.curryhydrocarbons.ca

 

[JML]

The Metric System is a modern system devised to be a coherent system of units. The other system of abitrary values devised by the UK/GB and adopted/adjusted by the USA is simply a museum piece and a pain in the proverbial to use.

In defence of the 'old' sytem it suited the measurements expected at the time; chains, furlongs, slugs, pounds, ounces etc. Not so much these days.

I don't think there is any argument for the old system except that old fuddy-duddies, (do you have that expression in the US? It means anyone old and boring in the UK - hey not my definition. I qualify as one), like to be able to demonstrate their ability with it. They are dying out though!

Come on you guys join the real world and dump the inch/foot/slug world. No one says that you can't still specify cycle threads for; err, umm ... cycle applications. Or Unified Fine for whatever. Some of those applications will continue to be relevant - we still make Whitworth and BSF bolts and nuts.

It's easier and more sensible ..... till the next one!