Measurement and precision.

Is your device accurate? How accurate is your device?

These two questions and their variations are regularly asked. Precision seems to be the holy grail of measurement.

Before answering whether a device is accurate, it makes more sense to consider what accuracy is.

The Larousse dictionary gives the following definition: Overall quality of a measurement or of an instrument capable of giving very nearly the same result when the same measurement is repeated several times.

Meanwhile the VIM (International Vocabulary of Metrology) gives the following explanation on the absence of the term precision in their document:

The French term "precision" has been used in the past to express so many different concepts that the authors of the 3rd edition of the VIM preferred not to use it in order to avoid any misunderstanding and chose the term "fidelity of measurement" .

So there seems to be a problem with this word. Indeed, in the common language, that of the “Muggles” of the measurement, the term precision or precise, indicates a device which gives a correct, good value, representative of reality.

In the language of measurement experts, the term precision should be banned, like the name of the villain in Harry Potter, which I dare not write here.

 

But then does a precise measuring device exist?

Yes ! and that for sure. For the simple reason that this is what the customer is looking to buy. It is the responsibility of measurement professionals to instruct and train the client to use the correct language. But first you have to understand the customer's need to make him “specify” what precise means for him. Is it repeatability? is it a low measurement uncertainty? etc.

The members of the Measurement Network are the perfect interlocutors to answer your questions, listen to you, guide you and provide you with this famous precise instrument.

We could talk here about certificates of calibration, conformity, "calibration" and others, because they are the ones that define part of the precision of the devices and that often demanded by customers. But the subject being complex I invite you to come back soon to discover this subject.

Hope this article will help you understand the measurement better and be accurate enough.