Keeping things in order

Lindfield scientists will head to Paris this September to represent Australia at the bi-annual committee meeting of the International Bureau of Weights and Measures.

Exact measurements are usually taken for granted. The humble metre is often exchanged for a rough estimate with paces. However, a group of scientists in Lindfield are putting the magic back into the metre, bringing measurements down to exact scientific equations in their work for the National Measurement Institute (NMI).

One such scientist is Nick Brown, who will be heading to Paris this September to represent Australia at a bi-annual committee meeting attended by delegates from around the world. This is part of the work of the International Bureau of Weights and Measures (BIPM). The purpose of this meeting? To ensure that the Australian metre is the same as every other metre around the world.

Brown says the conference isn't an exercise in being pedantic, it serves "to make sure that the metre we use is linked to the International Standard". This ensures that there is complete uniformity for measurement units.

"This is important for industry. Aircraft are built all over the world, for example, Australia built the ailerons of a recent Boeing airliner. Bearings can be made in one country and used in an engine in another. It is vital that these are correctly measured so they all eventually fit together."

The meetings at the BIPM are now also focussing on how to bring the third world countries up to speed, which will "lift developing countries up to a level where they can take part in international industry and trade. We are establishing a process for recognising the competence of their NMI through accreditation and testing."

The National Measurement Institute deals not only with distances. Frequency, mass, time and many other quantities are also watched carefully by Brown and his fellow scientists. Their work is responsible for maintaining Australia's units and standards of measurement and coordinating Australia's national measurement system.

So for all those who say measure twice, cut once; these scientists will tell you, measure once with a laser interferometer for the most precise measurement!

Next time you're measuring a metre of material for sewing or your cupboard space for carpentry, remember: a true metre is the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second. Or you could just let the Measurement Institute figure that out for you.