wtw inoLab 740, Operating Manual

Page: 84 / 274

pH
84
Three-point
calibration
Four-point
calibration
13 Thoroughly rinse the electrode with deionized water.
14 If necessary, set the temperature of the third buffer
solution with
82
(see section 5.5.1).
15 Immerse the electrode and the temperature probe in
the third buffer solution.
16 Press the
g
key.
The
h
display indicator flashes.
The electrode voltage (mV) appears on the display.
As soon as a stable value is reached,
h
disappears.
The probe symbol shows the calibration evaluation
after the three-point calibration.
The value of the slope S (in mV/pH) and the value of
the asymmetry (in mV) appear on the display.
17 Use
g
to go on to the four-point calibration
( ct4 appears on the display)
or terminate after the three-point calibration with
m
(the current calibration data are stored).
18 Thoroughly rinse the electrode with deionized water.
19 If necessary, set the temperature of the fourth buffer
solution with
82
(see section 5.5.1).
20 Immerse the electrode and the temperature probe in
the fourth buffer solution.