Measurement & Calibration Flashcards
7 cards from real CPT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Measurement & Calibration flashcards as text
A Gage R&R study is conducted and the %GRR result is 18%. According to AIAG guidelines, this result is:
Answer: Marginal and may be acceptable depending on application
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.
What is the primary purpose of a calibration interval?
Answer: To determine how frequently an instrument must be recalibrated to maintain confidence in its accuracy
Calibration intervals define the maximum time between calibrations to ensure the instrument remains accurate and fit for its intended use.
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?
Answer: Granite has a lower coefficient of thermal expansion and does not rust
Granite is preferred because it is dimensionally stable, has a very low thermal expansion coefficient, and does not rust or burr like metal plates.
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:
Answer: Poor repeatability
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.
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?
Answer: 1.213 inches
The vernier scale reading is added to the main scale reading: 1.200 + 0.013 = 1.213 inches.
Which type of measurement error cannot be corrected by calibration because it occurs randomly during use?
Answer: Random error
Random errors have no predictable pattern and can only be minimized by taking multiple readings and averaging; calibration corrects systematic errors, not random ones.
An out-of-calibration instrument is discovered after it has been used to inspect parts for the past month. The FIRST action a technician should take is:
Answer: Notify the quality department and quarantine or re-inspect affected parts
When an out-of-calibration condition is discovered, affected product must be quarantined and evaluated for disposition; the quality department must be notified per standard nonconformance procedures.