Tanker physics

I'm currently at the Metrology Society of Australasia conference in beautiful Queenstown. For those that don't know, which might be most of you, metrology is the science of measurement. How do you measure things well?

At this conference, we've got presentations on measuring temperature, pressure, liquid volume (a surprisingly tricky one this – if you want to do it accurately, quickly and non-destructively), electrical properties, so on and so forth. There's lots of industry engagement here – unsurprising since making measurements well can make real differences in a company's bottom line.

For example, Richard Suckling from Fonterra talked this morning about some of the problems that Fonterra faces in terms of collecting milk from farms, and the measurement technology that is packed into each milk tanker. Milk tanker routing is a real example of a 'travelling salesman problem' – how do you optimise the route that a tanker takes to go between all its pick-up points? There's a lot of computer power that goes into doing just that – to ensure that the minimum number of tankers are sent out, they arrive within time constraints, with enough spare capacity to take on board the milk, but with enough weight on board already in the right part of the truck  to get traction of the more tricky farm tracks, be able to turn in and out of the farm safely and so on. Coupled with large seasonal changes in milk production, optimized tanker routing means lower fuel costs, and that's a huge saving. Then there's all the technology that goes into measuring just how much milk is being taken onboard at each farm, monitoring the temperature of the milk, taking samples for testing quality, and so on. This is just collecting the milk. He didn't go into what happens after that.

But for me the most interesting comment was regarding the colouring and finish of the tankers, because it has parallels with military stealth technology , the area in which I used to work. There was a time when the tankers were just shiny metal, but a series of night-time accidents changed that. Several incidents occured where cars (with headlights on) drove into the sides of tankers. The shiny metal just wasn't visible at night, even when illuminated with a car's headlights? Why? The shape was such that the large majority of the light from the car was reflected away from the car. Only a small fraction was reflected back to where it came from, meaning that the driver wouldn't necessarily see the large object straight in front of him. The current finish, including retroreflective paint and diffuse surfaces is much easier to see at night – and can be made into a nice attractive logo to boot.

This afternoon we had an industry 'site visit' to Gibbston Valley Winery, to check out the measurement technology involved in the wine-making industry. Sugar content, pH, yeast content, etc, all need to be measured (Or so some winemakers say. Others just go on 'experience'.) And there were lots of nice samples for us to 'measure' too…

I'm sure we'll get a good lot of talks tomorrow, too.



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