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Metrohm 781 pH/Ion Meter User Manual

Page 101

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7 Various functions

780/781 pH/Ion Meter, Manual

91

variance
If at least 4 standards have been measured then the calibration function

will be calculated iteratively according to the principle of the smallest

mean-square error. The resulting variance will be given here. However,

if the value calculated for c(blank) is sufficiently small then the variance

will be given after only three standards have been measured. A more

detailed explanation of these calculations is given in Section 9.2.2.
Each subsequent manual alteration of the calibration data slope, pH(0)

and c(blank) will be documented by the entry '

manual

' against these

parameters

no.of standards
The number of standards actually measured will be given here. This can

be lower than that given in the calibration parameters, as a calibration

can be terminated prematurely with ; only the standards which

have already been measured will then be used for the calculation of the

calibration data.

cal.table:

original, delete n, reset cal.

This entry can be used to delete individual buffers from the calibration

table ('

delete n

') or to delete all the calibration data of an electrode Id

('

reset cal.

').

original
If you use