Component of variance analysis
Variance component analysis ( English Variance Component Analysis , VCA ) is a mathematical procedure for the statistical evaluation of measurement data. See also Tapio standard T545 of the Technical Association of the Pulp and Paper Industry (Tappi).
This calculation is used, for example, in the paper industry for the gravimetric analysis of the basis weight of a paper web. A corresponding analysis can be carried out with the Tapio analyzer , for example .
Since the paper web to be analyzed has a two-dimensional dimension, it is to be broken down into 4 components. The coefficient of variation is assessed in each case (corresponds to the standard deviation / mean ).
- Total coefficient of variation
- CD coefficient of variation, i.e. That is, only the pure cross section is considered
- MD coefficient of variation, i.e. That is, only the pure longitudinal profile is considered
- Residual value coefficient of variation, d. H. entire profile minus CD and MD (thus, for example, disturbances can be assessed that run neither in MD nor in CD direction)