Testing commutability of other materials

Test the commutability of reference materials or processed samples with unprocessed samples.

You must fit a Deming regression to perform this task.

  1. On the Analyse-it ribbon tab, in the Method Comparison group, click Restrict to Group.
  2. In the Group / Color / Symbol drop-down list, select the variable indicating the type of sample.
  3. In the Restrict fit to group drop-down list, select the group of unprocessed samples.
  4. On the Fit Y on X task pane, in the Prediction band edit box, type 95%, and if required select the Familywise coverage check box.
  5. Click Recalculate.

The scatter plot shows the points in different colors depending on the type of sample. The fit is restricted to a unprocessed samples and the prediction band includes any additional samples that are commutable with the unprocessed samples. A table lists the additional samples and if they are commutable with the unprocessed samples.