Siemens RAPIDLAB 248, Operator'S Manual, Page: 23 / 135

Calibration
Flexible Time
The 248 automatically calibrates as required and calculates the time
between calibrations to optimize performance. The maximum time interval
between calibrations is user-selectable and can be 30 or 60 minutes. The
time between 1 point calibrations will be between 10 minutes and the
maximum time interval selected. A full 2 point calibration is carried out at
every fourth interval.
For example:
When the interval is set to 30 minutes, the 248 automatically carries
out a 1 point calibration at least once every 30 minutes and a 2 point
calibration at least every 2 hours.
General
In both fixed and flexible time methods, the 248 automatically
calibrates after certain maintenance routines, for example, the
Disinfect , Deproteinize and Condition routines. It also calibrates if a
sampling fault occurs, for example ‘Sample not detected’.
QC
Siemens recommends that a Quality Control program is set up to
monitor instrument and operator performance. Because the needs of
each laboratory are different, due to size of workload, number of hours
worked, statutory regulations and so on, no attempt has been made to
formulate a rigid program. Users should follow local regulatory
guidelines to establish a QC program.
Use only Siemens approved QC materials. If you report your results to a
quality control statistical program, make sure they are informed of the
analyzer - Siemens 248 pH/Blood Gas Analyzer.
QC Handling
Significant errors in QC measurements may be caused by:
• improper storage and temperature equilibration of the QC sample,
• improper mixing of the QC sample,
• contamination of the QC sample by room air.
Always follow the manufacturer’s instructions for use carefully,
especially regarding the temperature of the QC before sampling. Mix
the ampule thoroughly, and once opened sample the QC immediately.
Do not re-use an opened ampule. Position the probe near the bottom of
the ampule to obtain a representative sample.
See references 1 - 4 for further information on Quality Control.
Understanding the System Page 1-13