The Data tab of the linearity and bias folio contains a control panel and a sheet with the following four columns for entering data:
Part is the identifier for the part that was measured.
Reference is the "true" value of the measured part (also called the master value). If the true value is unknown, the reference value can be the average of several measurements obtained via the most accurate measuring equipment available.
Reading is the measurement obtained from the gage under investigation.
Trial is used to help you keep track of multiple trials that are used in a particular study. For example, the first measurement of every part would be considered trial #1, the second measurement trial #2, and so on (as shown in the example data set below). These values are not used in the calculations.
As an example, suppose a gage was used to measure the diameter of two objects. The first object is 2 inches in diameter, and the second is 4 inches. Each object was measured five times. The resulting data set is shown next. For example, the first row shows that Part 1 has an actual diameter of 2 inches, but the gage produced a measurement of 1.95 inches.