Early Risers.

[AndyID]

12 minutes ago, Barry O said:

Big problem with diesel is that we add NoX (to gain performance) then add "Adblue" (cow  fluids to get rid of the NoX which rots Tarmac).

 

 

We don't actually "add" NOx. Both the N and the O are already in the air. To be efficient diesel engines have high combustion temperatures and it's the high temperatures that produce the oxides of nitrogen. (Here, diesel exhaust fluid (DEF) is sometimes referred to as "sealion whizz". )

[Tony_S]

At school engineering and woodwork were imperial. Science was metric but went  from cgs to mks to SI. University depended on the course. The spectroscopists used reciprocal cm for frequency, some of the physicists were angstrom users and some even used  a unit called the barn for the area of nuclei. By the time I started teaching nearly everything was SI. 

Tony

 

[Compound2632]

Ah yes, customary units - every trade has them. I'm ashamed to admit that my doctoral thesis included a simplified energy level diagram of a hydrogen-like silicon ion in which the energy levels were given in reciprocal cm, the laser light driving the transition between energy levels in nm, and the resultant emitted X-ray in keV...

[AndyID]

Messages sent to both of our state's US senators.  Best not say here what they were about.

 

What is it with ERs and knees? The waters on my knee have failed to subside so I thought I better talk to my doc to find out what options I have, if any.

 

Phoned for an appointment at 10:30. "Can you come in at 2:15?"

[AndyID]

5 minutes ago, Tony_S said:

At school engineering and woodwork were imperial. Science was metric but went  from cgs to mks to SI. University depended on the course. The spectroscopists used reciprocal cm for frequency, some of the physicists were angstrom users and some even used  a unit called the barn for the area of nuclei. By the time I started teaching nearly everything was SI. 

Tony

 

 

The trades and professions like to use their own measurement systems. A cynic might suggest it's a form of job preservation but it's probably more historical than anything else. The one that took me a while to understand was "tons" as applied to air conditioning systems.

[Coombe Barton]

https://johncolby.wordpress.com/2019/07/18/sandys-treatment-day-212/

[New Haven Neil]

48 minutes ago, AndyID said:

 

That's because, as Jamie might have it, it's le coqueup. It's a gauge rather than a scale.

 

Well yes, but there are two gauges. But a coqueup, agreed!  LGB (the model manufacturers....) have a lot to answer for - scale modelling with a variable scale - their MO is to make everything to a common loading gauge, and fudge the scale to suit.  Worked for them for years.

[Coombe Barton]

Towing a caravan with a hybrid is almost impossible. The weight limits are not high enough.

[New Haven Neil]

PS - Anyone remember the Merioneth Society article in Model Railways?  

[Tony_S]

6 minutes ago, Coombe Barton said:

Towing a caravan with a hybrid is almost impossible. The weight limits are not high enough.

It would be a problem for my car too.

No tow bar.

[PhilJ W]

Evening all from Estuary-Land. I still think about car fuel consumption in terms of miles per gallon, not so easy now that petrol comes in litres. Although once after a day out I realised that I had done 10 miles per litre so the mpg was easy to calculate at 46 mpg (1 gallon = 4.6 litres).

1 hour ago, Andrew P said:

A word of warning to all.

 

Do not solder standing up with sandals on.

 

1 hour ago, jamie92208 said:

Or above your head when under a baseboard.

 

Jamie

GDB is strangely quiet?

[Compound2632]

1 hour ago, Compound2632 said:

 

In principle, as a former metrologist, I agree. However, where one has different units for the same quantity, they can be expressed as a ratio, as in, 1 ft = 304.8 mm; in the quantity calculus this can be written: ft / mm = 304.8; this is simply a number, or in the language of the quantity calculus, a quantity with dimension 1. A scale also has dimension 1. The scale in which I model is 1 / 76.2. I am at liberty to multiply this by my ratio of units, yielding  ft / mm = 4, i.e., my scale is 4 mm / ft.

 

Ordnance Survey maps used to have a scale of 1 / 63,360, which is far from helpful to the traveller. But as mile / inch = 63,360, this problem was ovecome by describing the scale as 1 inch / mile. Even now, with maps at 1 / 50,000, understanding the scale as 2 cm / km is much more useful. The 1 / 25,000 maps, scale 4 cm /km, are handily close to 2.5 inch / mile...

 

Apologies for returning to worry this bone, but I realised there's a much more direct way of answering the criticism that 4 mm/ft isn't a scale:

 

1 ft = 304.8 mm

 

therefore

 

1 / 76.2 = 4 mm / ft.

[pH]

4 hours ago, Ozexpatriate said:

I often wonder when we can throw off the yoke of the old units, particularly in the US. I find it ironic that a country that enthusiastically celebrates it's separation from Britain every July, cleaves so tightly to antique British measures.

 

I know of an oil industry structure which was built in two parts - upper and lower. The parts were built in different countries and then joined. One part was built in imperial, the other in SI units. An interface section was needed to connect the two parts.

[pH]

1 hour ago, AndyID said:

Messages sent to both of our state's US senators.  Best not say here what they were about.

 

One of your senators has a very unfortunate name!

[AndyID]

1 hour ago, New Haven Neil said:

 

Well yes, but there are two gauges. But a coqueup, agreed!  LGB (the model manufacturers....) have a lot to answer for - scale modelling with a variable scale - their MO is to make everything to a common loading gauge, and fudge the scale to suit.  Worked for them for years.

 

Crikey! I thought it was all 45 mm gauge. What's the other one?

[brianusa]

4 hours ago, Ozexpatriate said:

 

Australia moved to a decimal currency in 1966 and to full metric adoption in 1974. This meant I never used the old money but am conversant in most Imperial and metric units, though living in the US I tend to think of measuring fuel efficiency in miles per gallon rather than km per litre.

 

I often wonder when we can throw off the yoke of the old units, particularly in the US. I find it ironic that a country that enthusiastically celebrates it's separation from Britain every July, cleaves so tightly to antique British measures. Nor does it help that Imperial liquid measures are different in the US - all your miles per gallon numbers will be 20% better than comparable data in the US.  It's all a mish mash. Here, soda is commonly purchased in 2l bottles and 12 oz (~375ml) cans.

 

When did Britain move to weather forecasts in Celsius? The advantages of Celsius with freezing weather are obvious, though I will say that the wider Fahrenheit scale is handier with warmer temperatures. 

 

I left in 1963, pre decimal currency, temps and measurements and while money was an easy adjustment, we still have the same old feet and inches, ozs and lbs, pts, qts and galls, while neighbouring countries are metric centric.  It is doubtful whether the US will ever change; its been tried but got nowhere yet metric is extensively used in government and business but I doubt the average Joe will ever be ready to make the change.

      Brian.

[AndyID]

13 minutes ago, pH said:

 

I know of an oil industry structure which was built in two parts - upper and lower. The parts were built in different countries and then joined. One part was built in imperial, the other in SI units. An interface section was needed to connect the two parts.

 

Not exactly unit related but a friend of mine worked for a certain boiler making concern that you are probably quite familiar with. He told me that on one occasion they made a very expensive boiler for a power station in England. On arrival at the power station it was discovered that some of the boiler's plumbing was mirror-image from the power station's plumbing. I never heard how they solved the problem.

[New Haven Neil]

11 minutes ago, AndyID said:

 

Crikey! I thought it was all 45 mm gauge. What's the other one?

 

32mm.  Most popular in the old country.  Some actually use 16mm scale, many just play trains.  known as SM32 and G45 generally - in the trade anyway as that is the nomenclature Peco use.

[pH]

51 minutes ago, AndyID said:

Not exactly unit related but a friend of mine worked for a certain boiler making concern that you are probably quite familiar with.

 

If it's the one I'm thinking of, I lived kitty-corner (there's a good North American expression!) across the railway from their works for my first six years.

[Ozexpatriate]

5 hours ago, jamie92208 said:

The fun bit came at Uni, where our Electrics and Electronics lecturer started taking about some strange things called ESU's IIRC.

Coulombs are a perfectly acceptable SI unit of electrical charge. The chemists and their cgs obsession serves to confuse. 

[Compound2632]

5 minutes ago, Ozexpatriate said:

Coulombs are a perfectly acceptable SI unit of electrical charge. The chemists and their cgs obsession serves to confuse. 

 

The coulomb, symbol C, is the SI unit of electric charge. Accept no substitutes.

[Ozexpatriate]

1 hour ago, brianusa said:

... we still have the same old feet and inches, ozs and lbs, pts, qts and galls

Except that the fluid ounces, pints, quarts and gallons are a different measure. As is the ton (the US 'short' ton).

 

1 hour ago, brianusa said:

It is doubtful whether the US will ever change; its been tried but got nowhere yet metric is extensively used in government and business but I doubt the average Joe will ever be ready to make the change

I live in hope. It really isn't that hard. Australia and Canada both did it with barely an issue.

 

The biggest complainers in 1974 in Australia were the horse racing fans who despaired that races would no longer be called in furlongs.

 

It's a silly emotional political thing. No politician wants to be associated with the blowback from people who don't want to change.

[Ozexpatriate]

17 minutes ago, pH said:

kitty-corner (there's a good North American expression!)

And fun to try to identify a conventional spelling. It is one of those expressions used much more often verbally than in print.

I think "cater-corner" is more 'formally' accepted, for whatever that is worth.

[Ozexpatriate]

5 hours ago, Compound2632 said:

... my doctoral thesis included a simplified energy level diagram of a hydrogen-like silicon ion in which the energy levels were given in reciprocal cm, the laser light driving the transition between energy levels in nm, and the resultant emitted X-ray in keV

That's a truly wondrous hash of units. Couldn't you have fitted an Angstrom in there somewhere?

 

I wanted to mark the post as funny but did not want to disparage your thesis. It is interesting to see energy in so many different legacy units yet none of them are Joules.

 

The semiconductor world is still beset by problems related to Imperial units. Semiconductors are designed in metric units. Dimensions for semiconductor packaging still involves deeply vestigial Imperial units based on "mils" (1⁄1000") which are not to be confused with mm. Britons would refer to this as a "thou".  Trying to accommodate design data based on both data sets can present serious resolution problems for software packages.

 

Edited July 18, 2019 by Ozexpatriate

[Tony_S]

1 hour ago, AndyID said:

 

Not exactly unit related but a friend of mine worked for a certain boiler making concern that you are probably quite familiar with. He told me that on one occasion they made a very expensive boiler for a power station in England. On arrival at the power station it was discovered that some of the boiler's plumbing was mirror-image from the power station's plumbing. I never heard how they solved the problem.

After he gave us his job as a product design engineer (due to stress) in an engineering company Dad took a Job on the inspection team in a company that made parts for the aircraft industry. One day he was presented with a prototype part to measure. He said he couldn’t as the part was not the same as the diagram. He got quite verbally abused by the manager who said he didn’t know what he was talking about and should accept that he did. Dad insisted later that the apology was delivered as loudly as the criticism. Dad said he even offered to explain about first and third angle projections in any future situation. 

Tony