Variance Coefficient

Location:

Report Variable (Peak Calibration)

Type:

Floating point number

Dimension:

%

Value Range:

 

Default:

 

Related Parameters:

Variance

Description:

The Variance Coefficient calibration variable can be considered a type of normalized Variance value. In Chromeleon, the variance coefficient is expressed in percent. This Chromeleon variable is especially useful when comparing variances of different peaks with different concentrations. A variance coefficient near zero means that the calibration curve well approximates the calibration points.

Thus, the variance coefficient indicates how well the data points correspond to the theoretically assumed course of the curve. Similar to the Coefficient of Determination and in contrast to the Correlation Coefficient it depends on the calibration type.

Function:

The mathematical description of the variance coefficient is as follows:

 

 

N:

Number of standard samples involved in the calibration,

i:

Index for standard samples,

F(x):

Model function of the calibration,

Xi:

X-value of the standard sample no. i,

Yi:

Y-value of the standard sample no. i,

Wi:

Weight factor of the standard sample no. i.