Metrology is an important term to understand, but it is a term that is widely used to mean a number of things. In basic form, metrology is the science of measurement. What this tells us, though, is that measurement is far from a perfect solution. In many cases, people will cause there to be a small amount of error in any measurement that is taken. In metrology, this is examined and explored fully.
An example that you may be able to relate to if you do not have any understanding of metrology is quite simple. If you need to measure a length of wood you would think that there is only one right answer as to how much wood is there. But, in fact, this is not a perfect answer. For example, you measured that wood using a piece of string. Then, the next person measured it as well. Why would the two units be different? Depending on the way the individual held the string including how taut the string was pulled will affect the overall outcome of the measurement.
Metrology goes far beyond that though. It studies many types of measurements. It studies not only length as in the example above but also such measurements as weight and time. Each and every one of these elements can be studied in various manners as well. In metrology, there are set standards that are set for measurement qualities to determine what the typical measurement is. In many cases, they will also have a well thought out plan as to how much of a degree of error there is as well in each measurement.
There are various answers to questions about metrology because, in many cases, each theory can be right. Metrology goes back thousands of years to early civilization and was present well before the aspects of science as well. Metrology can be fully explored throughout the web.