PROMGT3 (Lecture 9 and 10) Flashcards
Science of measurement
Metrology
This term refers to “measuring examining, testing, or gauging one or more product or service characteristics and comparing the results with specified requirements to determine whether conformity is achieved for each characteristic”.
Inspection
This term refers to “appraising characteristics of supplies, components, and so forth, that involves the application of scientific and laboratory methods mostly functional.”
Testing
Examples of Variable Gauges
Rulers
Calipers
Micrometers
Optical Gauges
Examples of Fixed Gauges
Feeler Gauges
Ring Gauges
Plug Gauges
Go No-Go Gauges
Closeness of agreement between the average of a large number of experimental measurements of a characteristic and the master value of that characteristic
Accuracy
Difference between the average value of all the measurements and the master value. It is the numerical value used to measure accuracy
Bias
Measure of the degree of repeatability between measurements.
Precision
Variation in measurements is observed when one operator repeatedly measures the same characteristic in the same place on the same part with the same gauge
Repeatability
Variation in average measurements due to factors other than the machine variation. It is the variation that results when different conditions are used to make the measurements of the same characteristic.
Reproducibility
Types of Gauge R & R Studies
Short Method Study
Long Method Study
Type of method study conducted to determine quickly the composite gauge variation
Short Method Study
Type of method study that allows the determination of errors of gauge repeatability and reproducibility separately. This facilitates the determination of assignable causes when the gauge is not performing its functions
Long Method Study
