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2. Measurement Process Characterization
2.6. Case studies
2.6.2. Check standard for resistivity measurements

2.6.2.5.

Run check standard example yourself

View of Dataplot macros for this case study This page allows you to repeat the analysis outlined in the case study description on the previous page using Dataplot. It is required that you have already downloaded and installed Dataplot and configured your browser to run Dataplot. Output from each analysis step below will be displayed in one or more of the Dataplot windows. The four main windows are the Output Window, the Graphics window, the Command History window, and the data sheet window. Across the top of the main windows there are menus for executing Dataplot commands. Across the bottom is a command entry window where commands can be typed in.
Data Analysis Steps
Results and Conclusions
Click on the links below to start Dataplot and run this case study yourself. Each step may use results from previous steps, so please be patient. Wait until the software verifies that the current step is complete before clicking on the next step. The links in this column will connect you with more detailed information about each analysis step from the case study description.
Graphical tests of assumptions
Histogram

Normal probability plot

The histogram and normal probability plots show no evidence of non-normality.
Control chart for precision

Control chart for probe #2362

Computations:

  1. Pooled repeatability standard deviation
  2. Control limit

The precision control chart shows two points exceeding the upper control limit. We expect 5% of the standard deviations to exceed the UCL even when the measurement process is in-control.

Control chart for check standard

Control chart for check standard #137

Computations:

  1. Average check standard value
  2. Process standard deviation
  3. Upper and lower control limits

The Shewhart control chart shows that the points scatter randomly about the center line with no serious problems, although one point exceeds the upper control limit and one point exceeds the lower control limit by a small amount. The conclusion is that there is no evidence of bias or lack of long-term control.
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