In past columns we've looked at "basic" comparative height gages, which are used for layout tasks and other surface plate measurements. These consist of a comparator stand, plus a test indicator or an electronic gage head and amplifier.
Just as there is no repeatable way to make a perfect part, and there is no repeatable way to make a perfect measurement. Thus, the question is always one of uncertainty: how imperfect is my measurement and how can I make it less imperfect?
Last month we began a series looking at various aspects of the electronic gaging process with an eye towards reducing uncertainty and making measurements "less imperfect." This month, we'll look at probes.
The right angle is one of those things that man has created in his mind. In nature it only happens by chance. But the importance of this concept which results from the perpendicular intersection of lines or surfaces applies to architecture, civil engineering, agriculture and manufacturing.
Many parts manufactured today have functional requirements to mate with parts that will have either a rotational or linear motion. When the design engineer builds these requirements into a part there will be tolerances specified for straightness and roundness, or even cylindricity which is the combination of both.