Download SEBA - TERM

SEBA HYDROMETRIE, user manual
2.8.4 Calibration / pH
2.8.4.1 Calibration / pH / 2-point
The pH-electrode will be adjusted with two buffer solutions. An automatic and a manual mode can be
selected. The calibration will be effected in two phases. In phase1 the pH-electrode will be dipped into
buffer 1 together with the temperature sensor. After the first measurement (pic. 2.8.4.1.1) the sensors
will be cleaned and then the electrode voltage will be measured in buffer 2. In case of an error code,
phase 2 can be repeated. After finishing phase 2 the calibration result (pic. 2.8.4.1.2) will be indicated.
The slope of the electrodes will be determined in mV/pH and their drift since the last calibration.
Moreover the offset voltage at the isothermal point of intersection, generally at pH7 in mV and the offset
drift since the last calibration in pH-units will be indicated. With these data the drift in the measuring
period can be determined and the status of the electrode can be estimated. The calibration intervals can
be effected according to the accuracy requirements of the user. The measuring values can be
compensated nearly linear for this time (formula 2.8.4.1). For quality securing the calibration data can be
printed and put into the archives.
Attention! Observe the safety instructions for use with buffer solutions. The buffer solutions have
to be handled carefully - as chemicals.
pic: 2.8.4.1.1
- 26/48 -