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material and the environment, the operations that make it possible to
get the measurement, i.e. everything related to the carrying out of
these measurements, must be written in a document and will be taken
into account particularly when choosing the operators. One of the very
first principles of quality assurance is to write down what is being
done. This process is simple and allows people to think further about
the choice of the method. There must be a clear distinction between
chosing a method and chosing a measuring instrument. For example,
you may want to measure a dimension on a rubber part: you happen to
be close to a three-dimensional measuring machine and your instant
reaction may be to go to this machine without thinking whether there
may be a more suitable method than this one.
Defining the method and the principle to implement
When there are several methods of measurement, it is often
difficult to determine which one will best fit your need if you are not
able to classify them. Our advice is to keep only the two (maybe three)
most important criteria in mind.
As a rule, there are in metrology three great principles of measurement;
the three of them have advantages and drawbacks.
They are:
– differential measurement;
– direct measurement;
– indirect measurement.

III Answer the questions:
1 What must the choice of the selected method take into consideration?
2 When may you have to qualify the method of measurement?
3 Who can help you in choosing the method of measurement?
4 What will be taken into account when choosing the operators?
5 What is one of first principles of quality assurance?

IV Fill in the blanks with appropriate words:
1 Within the scope of some contracts you may 1 quality
have … the method of measurement. assurance
2 It is often possible … to the methods which 2 subjected
are known and officially accepted. 3 to qualify
3 Whether the method … or not it is important 4 is qualified
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