Roche cobas b 221 system

Roche Diagnostics May 2009
Service Manual · Version 9.0 D-73
cobas b 221 system 7 Troubleshooting
Value flag s
Possible causes: o An air bubble has falsified the calibration
o Defective electrode
o Unhomogenous O
2
zero point solution
Remedy: o Perform "Calibration for Ready".
o Call up "Wetting routine" for BG.
h [System] > [Utilities] > [Fluid actions] > [Wetting routines].
o Call up fill routine "Aspirate solution O2 zero". h [System] > [Utilities] >
[Fluid actions] > [Fill routines] > [Aspirate solution O2 zero].
o Replace S2 Fluid Pack.
o Replace PO
2
electrode.
o Insert electrode simulator and act accordingly.
Flag no. 2021 "Drift alarm"
A drifting of the sensor signal was detected in the "Ready" state.
Possible causes: o The electrode drifts exceed the default limit values
o Invalid sample type used
o Wetting problems
o PO
2
contamination
Remedy: o Perform "Calibration for Ready".
o Call up "Wetting routine" for BG.
h [System] > [Utilities] > [Fluid actions] > [Wetting routines].
o Call up the stability monitor and check "Details" of the "Electrode slope". If the
electrode/cartridge is defective, it is displayed. Replace the corresponding
electrode or cartridge.
e For the details, see Stability monitor on page D-120.
o If the flag refers to the PO
2
electrode, call up "Aspirate MIX 1" in the meas. sensors
test for BG.
e For the details, see Meas. sensors on page D-103.
The standard deviation of the PO
2
sensor signal must be no greater than 50 mV
within two minutes.
O If the standard deviation was too high, perform "Internal cleaning" for BG.
h [System] > [Wash & cleaning] > [Cleaning modules]
O In case the error was resolved, set the interval for "BG cleaning" to 3 days.
h [Setup] > [Times & intervals] > [Maintenance timing]
Perform an "External cleaning" for BG with Deproteinizer if necessary.
o Insert electrode simulator and act accordingly.
Flag no. 2022 "Ref. drift alarm"
A drifting of the sensor signal was detected at the reference electrode in the "Ready"
state.
Possible causes: o Bubbles interfere with reference system