Unit 13: Mechanical operations
LO5: Be able to quality assure components
Planned quality assurance checks
Learner activity sheet
Activity 1: General dimensional metrology knowledge
Answer the following questions:
a) What is meant by the terms ‘accuracy’ and ‘precision’ when making measurements?
b) What is meant by the term ‘resolution’ of a measuring instrument?
c) If a dimension contains a tolerance of 100 microns, what does the capability of the chosen measuring
instrument need to be in order to provide a reliable measurement?
d) Illustrate a vernier scale and how to read it.
e) Sketch a micrometer, and label the various parts. Discuss the principle of its operation and how to
read it.
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Activity 2: Appropriate usage of measuring equipment in dimensional
metrology
Dimensional metrology is the measurement of geometric features of an object. This may involve
measuring the size, distance, angle, form or co-ordinate of features.
Using a suitable object (your teacher may select this for you) pick the appropriate measuring equipment
and measure the dimensions below:
a) Overall length
Measure the overall length of the object
b) Overall height
Measure the overall height of the object
c) Hole measurement
Measure the position (and depth if possible) of any holes in the object
d) Stepped face
Measure the height of any stepped faces on the object
e) Angle measurement
Measure the angle of any angled faces on the object
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