pH/Oxi 340i
pH calibration
7
pH calibration
AutoCal TEC
This process is specially adapted to the WTW technical buffer solutions as a
fully automatic single or two-point calibration. The buffer solutions are
automatically recognized by the measuring instrument. Depending on the
instrument setting, the instrument displays the relevant buffer nominal value
or the current electrode voltage in mV.
Valid buffer (values at 25 °C): 2.00 / 4.01 / 7.00 / 10.01
Note
The calibration for pH 10.01 is optimized for the WTW technical buffer solu-
tion TEP 10 Trace or TPL 10 Trace. Other buffer solutions can lead to an
erroneous calibration. The correct buffer solutions are given in the WTW
catalog or in the Internet.
AutoCal DIN
as AutoCal TEC, but matched to buffer solutions according to DIN 19266.
Valid buffer (values at 25 °C): 1.679 / 4.006 / 6.865 / 9.180
ConCal
is the conventional two-point calibration using two buffer solutions (pH 7.0
± 0.5 and any other buffer solution) or a single-point calibration using any
buffer solution and is used as a high-speed method.
Calibration
evaluation
After calibrating, the measuring instrument automatically evaluates the cali-
bration. The asymmetry and slope are evaluated separately. The worst eval-
uation appears on the display.
Display
Asymmetry[mV]
Slope [mV/pH]
-15 ... +15
-60.5 ... -58
-20 ... +20
-58 ... -57
-25 ... +25
-61 ... -60.5
or
-57 ... -56
Clean the electrode according
to the electrode operating
manual
-30 ... +30
-62 ... -61
or
-56 ... -50
E3
Invalid calibration
< -30 or > 30
< -62 or > -50
