Visual Inspection and Basics - Module 3

Question 1

One of the key steps when performing high accuracy measurements is making sure that the tool conforms to a standard. This is called…

Answer 1

Standardization or calibration.

Question 2

Considerations when choosing a measuring tool:

Answer 2

Quantity you need to measure

Geometric considerations

Desired accuracy, precision and resolution

Question 3

No matter what you attempt to measure, it is important to have the following:

Answer 3

• An understanding of the units you are using
• The right tool – choosing a tool that measures those units adequately
• Knowledge about how to operate the tool correctly

Question 4

Precision

Answer 4

How repeatable it is

Question 5

Accuracy

Answer 5

Closeness to the actual value

Question 6

Resolution

Answer 6

determined by the closeness of the increments on the measuring tool; the smaller the increments the better the resolution

Question 7

Parallax phenomenon occurs when…

Answer 7

…two objects at different distances from the eye appear differently in relation to each other as the viewing angle changes.

Question 8

Best way to reduce parallax…

Answer 8

be sure that you view the ruler straight on, or “square” to the surface

The greater the distance between the marks – the greater the chance of error in measurement.

The effects of parallax can also happen when viewing needles and dials (think of a car’s speedometer viewed from the passenger side), or any two marks removed from each other.

Question 9

3 types of callipers:

Answer 9

Vernier
Dial
Digital