beautypg.com

2 determining delta t, Determining delta t – Metrohm 873 Biodiesel Rancimat Manual User Manual

Page 58

background image

4.4 Calibration functions

■■■■■■■■■■■■■■■■■■■■■■

50

■■■■■■■■

873 Biodiesel Rancimat

Enter the conductivity of the standard used.

c(KCl) = 1 mmol/L can be used as a standard solution. This is derived
from the optionally available conductivity standard 6.2301.060
(KCl 0.1 mol/L) through dilution with distilled water. The conductivity
of this diluted solution is:

Temperature Conductivity

18 °C

19 °C

20 °C

21 °C

22 °C

23 °C

24 °C

25 °C

127 µS/cm

130 µS/cm

133 µS/cm

136 µS/cm

138 µS/cm

141 µS/cm

144 µS/cm

147 µS/cm

Alternatively, the conductivity standard 6.2324.000 (undiluted) can be
used.

3 Start determination and check the values

Click on [Start] to start the determination of the cell constant.

After the determination is finished, the dialog window Enter/Check
cell constants
appears again.

If you wish to accept the displayed values, click [OK].

If you wish to maintain the old values, click [Cancel].

4.4.2

Determining Delta T

The temperature correction Delta T indicates the deviation of the current
temperature of the sample from the temperature in the heating block and
belongs to the method as a parameter (see Chapter 4.5.2, page 60). It
can automatically be determined with the calibrated, external temperature
sensor (part of the optionally available GLP test set, see Optional accesso-
ries, page 180
).