CPT Measurement & Calibration 3

Question 1

A Gage R&R study is conducted and the %GRR result is 18%. According to AIAG guidelines, this result is:

Accepted Answer

Marginal and may be acceptable depending on application

Answer

AIAG MSA guidelines classify 10–30% GRR as marginal; acceptability depends on the importance of the application, cost of the gage, and cost of repairs.

Question 2

What is the primary purpose of a calibration interval?

Accepted Answer

To determine how frequently an instrument must be recalibrated to maintain confidence in its accuracy

Answer

Calibration intervals define the maximum time between calibrations to ensure the instrument remains accurate and fit for its intended use.

Question 3

A height gage is used on a granite surface plate. Why is a granite surface plate preferred over a steel surface plate for precision work?

Accepted Answer

Granite has a lower coefficient of thermal expansion and does not rust

Answer

Granite is preferred because it is dimensionally stable, has a very low thermal expansion coefficient, and does not rust or burr like metal plates.

Question 4

During a measurement process, a technician always gets a different reading each time they measure the same part with the same instrument. This variability is most likely caused by:

Accepted Answer

Poor repeatability

Answer

Repeatability is the variation in measurements obtained by one operator using the same instrument on the same part under the same conditions; high variation indicates poor repeatability.

Question 5

A vernier caliper has a main scale reading of 1.200 inches and the vernier scale indicates 0.013 inches. What is the correct reading?

Accepted Answer

1.213 inches

Answer

The vernier scale reading is added to the main scale reading: 1.200 + 0.013 = 1.213 inches.

(CPT) Certified Production Technician Practice Test

(CPT) Certified Production Technician Practice Test

CPT Measurement & Calibration 3