Roche cobas b 221 system User Manual

Roche Diagnostics May 2009
Service Manual · Version 9.0 D-123
cobas b 221 system 7 Troubleshooting
Important test routines
The electrode status is shown as number of electrode error entries in terms of quality
of the sensor. For each sensor, the following limit (in percentage) applies:
Electrode voltage scanning
Evaluates the characteristics of the adjusting curve of the electrode signals (during
each aspiration cycle).
Possible error causes: defective measuring chamber electronics, contamination in case
of PO
2
electrode.
Following items will be displayed in case of nOk – .
The electrode voltage scanning is shown as number of errors in the selected period.
For each parameter, the following limit (in percentage) applies:
Standard deviation
Evaluates the measuring quality (standard deviation) of several single measurement
points of the electrode adjusting curve.
Possible error causes: Air bubbles in the inner electrolyte of the electrodes, defective
grounding, defective measuring chamber electronics.
Item Description
Parameters
affected parameters
Each parameter may be listed more than once due to different
electrode status messages.
Standard deviation
number of parameter messages
If a parameter is listed more than once, each entry shows the totals for
this parameter.
Message
indication of the error;
h press [Details] for troubleshooting information
Appearance
number of parameter errors
Ta bl e D -9 Electrode status details
Sensor Limit value
all < 10 %
Ta bl e D -10 Electrode status evaluation
Item Description
Parameters
affected parameters
Error
number of parameter errors
Ta bl e D -1 1 Electrode voltage scanning details
Sensor Limit value
all < 5 %
Ta bl e D -1 2 Electrode voltage scanning evaluation

Roche cobas b 221 system Specifications

General

Brand	Roche
Model	cobas b 221 system
Category	Medical Equipment
Language	English