Road Signs: Time to change to Metric?

[pinballdave]

Originally Posted by Othen

I dimly recall a few old fashioned greengrocers and butchers being threatened with prosecution for keeping their imperial measure scales and balances (probably 40 years ago). I don't think anything has changed today.

From 1989 you had to use metric units when measuring, so the prohibition was on using imperial scales, not on the particular amount being sold.

The 'chapter and verse' is the European unit of measure directive, and yes it is true that this was intended to prohibit imperial measurements, but in practice the UK was always able to obtain derogations that would allow them still to be used.

The big change was in 1989, when the UK's previous derogation for allowing imperial units ran out, and in the replacement derogation the imperial unit was a considered a 'supplementary indication' and the formal measurement unit had to be metric. By 2009 the EU had given up arguing the point, and instead of yet another derogation, they changed the wording of the regulations to specifically include supplementary measurements.

But the point is, through all of this, you have always been free to advertise and sell in any quantity you desire, as long as (post 1989) the actual measurement is performed in metric units.

The mismatch of units in my example was intentional. There are no restrictions on what metric measurements you use, you can sell your spaghetti by length or volume as well as the more conventional weight.

[Othen]

Originally Posted by Baxlin

Re the PPS above.

Mrs B was checking out a new recipe yesterday, and one ingredient was “a pint of blueberries”, which, I seem to recall, are usually sold by weight...

Excusing my pedantry again: volumes and weights will generally be directly proportional (the density of the substance being pretty well constant) - hence it is fine to equate pounds with pints (for a given thing), but a length can never be proportional to a volume - the dimensions are different and have no proportionality.

Einfach, nicht wahr?

[pinballdave]

Originally Posted by Othen

but a length can never be proportional to a volume - the dimensions are different and have no proportionality.

Attempting to out-pedant the pedant, but for something that is a constant cross-sectional area (like spaghetti!), the length is proportional to the volume.

For something that is of consistent density and extruded, length, weight and volume are all proportional.

So you could quite happily settle on linguine as a measure of volume and weight as well as length.

[canis]

Right about the spaghetti. I used to manufacture reels of polythene. Because the gauge of the material was known(in thousandths of an inch), and the width (in inches), the length (in metres) was directly proportional to the weight (in pounds). So each reel was weighed to ensure it was correct.

[john.wigley]

Originally Posted by canis

Right about the spaghetti. I used to manufacture reels of polythene. Because the gauge of the material was known(in thousandths of an inch), and the width (in inches), the length (in metres) was directly proportional to the weight (in pounds). So each reel was weighed to ensure it was correct.

Interesting that you should also use a mix of units (as with tyres) 'canis'. Out of interest, was the finished reel weighed using Metric or Imperial units and / or a conversion factor?

I mind a time 40 years ago when I worked for a well-known lawn-mower manufacturer. With little more than new transfers, we rebranded our 12" model to become the new '30' and the 14" the new '35'. Ergo, with minimum upheaval on the production line, we (drum roll!) entered the metric age. The customers did not need to know, and probably weren't interested, that the basic design of the machines had remained unaltered for several decades!

Wish all things were that simple!

Regards, John.

[canis]

Originally Posted by john.wigley

Interesting that you should also use a mix of units (as with tyres) 'canis'. Out of interest, was the finished reel weighed using Metric or Imperial units and / or a conversion factor?

The reels were weighed usually imperial, unless the customer specifically wanted metric. Ministry of Defense, for example, would always insist on metric units.

I got very good at multiplying by 2.2 (double it, add ten percent)

[Baxlin]

Originally Posted by Othen

Excusing my pedantry again: volumes and weights will generally be directly proportional (the density of the substance being pretty well constant) - hence it is fine to equate pounds with pints (for a given thing), but a length can never be proportional to a volume - the dimensions are different and have no proportionality.

Einfach, nicht wahr?

Generally being the word here, you can get significantly more small items in a given volume than large ones, so if the density of the substance is pretty well constant, the weight could vary.

[Othen]

Originally Posted by Baxlin

Generally being the word here, you can get significantly more small items in a given volume than large ones, so if the density of the substance is pretty well constant, the weight could vary.

You are just pulling my leg, right?

Good fortune,

Alan

[Baxlin]

Originally Posted by Othen

You are just pulling my leg, right?

Good fortune,

Alan

Possibly, Alan, possibly not. Consider this...

Take some large strawberries, (or any fruit that can be large or small) and fill a container with them. Now empty them out, and cut them into small pieces, and put them back into the same container. Odds on it will now be nothing like full, but still the same weight, because you have replaced air with strawberries. You will need more small pieces to fill the pot, so a pint of small strawberries will weigh more than a pint of large ones, because there’s less air trapped between them.

I agree completely that if you can fill every cc of the container with the ‘product’, it won’t matter whether it’s small pieces or large (eg a container ship has different size containers, but they fit together), but in the kitchen with round fruit, it’s not the same density throughout, because of the air.

So, am I pulling your leg, or not? Is it ‘fake’ science, or not? You tell me.....
Malcolm

[Othen]

Originally Posted by Baxlin

Possibly, Alan, possibly not. Consider this...

Take some large strawberries, (or any fruit that can be large or small) and fill a container with them. Now empty them out, and cut them into small pieces, and put them back into the same container. Odds on it will now be nothing like full, but still the same weight, because you have replaced air with strawberries. You will need more small pieces to fill the pot, so a pint of small strawberries will weigh more than a pint of large ones, because there’s less air trapped between them.

I agree completely with you if you can fill every cc of the container with the ‘product’, it won’t matter whether it’s small pieces or large (eg a container ship has different size containers, but they fit together), but in the kitchen with round fruit, it’s not the same density throughout, because of the air.

So, am I pulling your leg, or not? Is it ‘fake’ science, or not? You tell me.....
Malcolm

Ha ha Malcolm,

If I take a strawberry weighing (let's say) 1 oz, and I put it in a large container, let's say a 1 gallon bucket, then the density of strawberries is 1 oz/gal. Okay, let's add another strawberry to the gallon bucket and I've beaten science by doubling the density of strawberries to 2 oz/gallon.

Do you think I'll get a Nobel prize for working out how to double the density of matter, after all if I keep adding strawberries I can make matter almost infinitely dense and so make my own nuclear fusion reactor in the shed?

Science eh! :-)

Alan