Variance

Location:

Report Variable (Peak Calibration)

Type:

Floating point number

Dimension:

-

Value Range:

 

Default:

 

Related Parameters:

Standard Deviation,

Variance Coefficient

Description:

The Variance calibration variable is the average deviation of all area values F from the corresponding ideal area value in a calibration. The ideal area value is the value at the point of intersection between the calculated calibration curve and the corresponding amount value.

Variance is therefore a criterion for the measuring accuracy in the calibration. With an increasing value, calibration points are increasingly scattered.

Note:

 

Extracting the square root of the variance value results in the Standard Deviation calibration variable; that is, the square standard deviation is the variance.

Function:

The mathematical description of the variance is as follows:

 

N:

Number of standard samples involved in the calibration,

m:

Number of coefficients to determine (depending on the Calibration Type: LIN: m = 1; LOFF: m = 2; QUAD: m = 2; QUOFF: m = 3 and EXP: m = 2),

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, and

D i:

Yi - F(Xi)