A gage linearity and bias study is conducted by choosing parts or samples that cover the operating range of the gage. For each part, multiple measurements are made and the average of the measurements is compared with the master part measurement.

A gage linearity and bias study uses the average of measurements and the master measurement to assess bias and linearity.

·    Bias tells you now accurate your gage is compared to a master value.

·    Linearity tells you how accurate your gage is through the expected range of measurements.

Five parts were chosen that represented the expected range of measurements. Each part was measured by layout inspection to determine its master measurement, then one operator randomly measured each part 12 times.

The Total Variation Study Variation from a Crossed Gage R&R study using the ANOVA method can be used as the Process Variation here. That value is 14.1941.

Data: MeasurementQuality.MTW (available in the Sample Data folder).