Roche Diagnostics May 2009
Service Manual · Version 9.0 A-33
cobas b 221 system 2 Fluid actions
Calibration
Calibrating the conductivity for
CAL B
In this section the conductivity of calibration solution CAL B is precisely measured in
the BG and ISE measuring chamber. The precision of this measurement is very
significant for Mix1 and Mix2, because they are based on this measurement.
CAL B is already in the sample distributor at V21. The BG measuring chamber is
cleaned with a mixture of air and CAL B after the FMS adjustment. Then the BG
measuring chamber is filled with CAL B with no air bubbles and the conductivity is
determined.
Then CAL B is aspirated into the ISE measuring chamber and also measured there.
Calibrating the conductivity for
CAL A
This procedure is similar to the calibration of the conductivity for CAL B, with the
only difference being that a FMS adjustment is not made first.