Lesson 2

In Try This 2 you probably noticed the following:

• You subtract the uncertainty to get the minimum limit of the measurement.
• You add the uncertainty to get the maximum limit of the measurement.

Now apply this knowledge in Self-Check 1 using an imperial measuring device.

 

Self-Check 1

 

Use the picture of the tennis ball to answer the following questions.

 

Determine the diameter of the tennis ball using an imperial 5-in ruler.

 

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Precision and uncertainty in measurements occur frequently on the job. The degree of uncertainty tolerated depends upon the type of measurement being taken and the ramifications of an inaccurate measurement.

 

Over time and after extended use, mechanical parts on equipment wear out and need to be replaced. When a machinist makes a new pin to replace a worn out one, he or she needs to be precise and within an amount of uncertainty to ensure the pin will fit and function properly.