Metrohm 719 S Titrino - Manual (Page 21)

2.4 Tutorial
719 S Titrino
17
2.4.4 pH calibration
For end-point titrations, however, where titration is performed to a fixed, specified pH
value, a calibration should be performed.
Selection of the calibration mode, CAL
<MODE>
<ENTER>
• Press <MODE> repeatedly until "CAL" appears in
the display and confirm the mode with <ENTER>.
The instrument is ready for a 2-point calibration. The
second display line shows the current calibration data
for measuring input 1.
Calibration procedure
<START>
<ENTER>
<ENTER>
<ENTER>
oder
<STOP>
• Immerse your electrode in the first buffer and start
the calibration procedure.
Inquiry of calibration temperature.
• Enter the current temperature. If you have a tem-
perature sensor connected, this inquiry is skipped.
pH value of the first buffer.
• Enter the pH value of the buffer at your calibration
temperature.
The voltage of the first buffer is measured. When the
measured value has met the set drift criterion, the
measurement is stopped and the pH value of the sec-
ond buffer is requested.
• Now enter the pH value of the second buffer. If you
require a 1-point calibration, you can also terminate
the calibration with <STOP>.
At the end of the calibration, the calibration data ob-
tained are displayed: asymmetry pH and slope.
The calibration data can be viewed at any time under the <CAL.DATA> key. Our calibra-
tion data are stored under ">input 1".
The calibration report can be printed out at any time with the key sequence:
<PRINT><CAL.DATA><ENTER>
mode
mode CAL
CAL ********
pH(as) 7.00 slope 1.000
CAL
cal.temp. 25.0°C
25.0°C
buffer 1 pH 7.00
25.0°C
buffer 2 pH 4.00
CAL ********
pH(as) 6.89 slope 0.985