Metrohm 763 PVC Thermomat Manual User Manual

Page 106

4.7 Results

763 PVC Thermomat

4.7.4

Extrapolation

Extrapolation window

763 PVC THERMOMAT RESULTS / Determination / Extrapolation

Opens the

Extrapolation

window in which the extrapolation values cal-

culated from the results of the determinations marked in the determina-

tion overview are displayed numerically and graphically. The extrapola-

tion is based on an exponential equation with the help of the result

quantities defined under

and

Target temperature

. Extrapolation

can be used to convert results measured at different temperatures to

the required target temperature. In addition this method can be used to

determine the

Factor

for converting the

induction time

into the

standard

time

The time determined for a particular sample by extrapolation to low

target temperatures (e.g. 25 °C) is a purely theoretical value. The

relationship between this time and, for example, the working life of the

sample must always be determined experimentally.

Extrapolation graph

In the Temperature vs. Time graph the line T = ln(t)/B – ln(A)/B, cal-

culated with the help of a linear regression, is shown. The measured

values of the selected determination are shown in black, the regression

line in green and the time calculated for the

Target temperature

in red.