In the grand scheme of things, the concept of interchangeable parts is relatively new. Manufacturers were actually allowed to use whatever measurements they wanted for most of history. That meant that something you bought in one town probably wouldn’t have fit screws or nails made somewhere else. Without metrology, we’d still be forced to deal with this level of confusion. We don’t have to, however, because great advances have been made in the study of measurement as these four real-world applications show.
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1. Eliminating Survey Feet
Land developers used to use two different definitions for the foot, which would then confuse factory managers who had to fill orders for them. The so-called survey foot was defined slightly differently from the international foot that most people use when they say that something is 12″ in length. The differences usually weren’t noticeable on paper, but they could lead to serious problems once a factory turned their machines on. Metrologists have agreed on one single definition for the foot, which has alleviated this problem.
2. Standardization
Perhaps nowhere has metrology shown more promise than in the field of standardization. Keep in mind that this has very little to do with the fact that an entire system of measurement is actually called standard. Rather, it refers to the way that dedicated measurement tool vendors are now capable of producing equipment that doesn’t differ across multiple iterations. For instance, if you bought a ruler on one day and then got a second identical one another there wouldn’t be any appreciable difference between the two. Those who aren’t used to precise manufacturing might not immediately see why this is such a huge step forward. When you’re working with something as small as a semiconductor, a variation of even less than 1/64″ could introduce serious irregularities in the manufacturing process.
3. Separating Weight and Mass
Contrary to popular belief, the international kilogram is actually a measurement of mass rather than weight. Pounds instead measure weight as a function of gravity on an object. Countless engineers and technicians have used the two units as though they both reflected the same thing, which leads to small differences in the ultimate specification of certain components. As a result, some small defects would occur when different teams converted between the two systems. Metrologists have brought more accurate tools that offer figures in both pounds and kilograms, thus making things much easier.
4. Reducing Returns
Lower levels of defective materials can quickly translate into fewer returns. Plant managers want to see as few products sent back as possible, since each of these represents both a loss of money as well as a source of waste. Attention to measurement details has helped to cut back on the amount of goods that get shipped back to their place of origin. This has been especially helpful in the automotive space, where individual pieces have to be made to extremely exact tolerances in order to meet regulatory requirements.
Within the manufacturing industry, a number of different factors have helped transform the industry into what it is today, and metrology is one of the main factors.
