Siemens RAPIDLAB 248, Operator'S Manual, Page: 91 / 135

Configuring the System Page 5-3
Selecting Calibration Method and Entering Gas Values
To select calibration option: from Ready press # for menu , 5 for
Operating Setup
and
4
for
Calibration
.
To choose calibration method and interval press 1 .
selected
not selected
To enter gas values press 2 .
The maximum ranges available for gas values are:
cal gas 4 - 6% CO
2
10 - 14% O
2
slope gas 8 - 12% CO
2
0 - 2% O
2
.
Default settings: flexible time, interval = 30 minutes.
Gas values Cal 5% CO
2
, 12% O
2
; Slope 10% CO
2
, 0% O
2
.
Setting Printer Options
The roll printer can be turned on or off, and can be set to print results
only, or results and calibrations.
To set printer options: from Ready press # for menu , 5 for
Operating Setup and 5 for Printer Options .
selected
not selected
Default setting: printer on, print results only.
Adjusting Correlation
The 248 is set during manufacture to give results which correlate with
tonometered blood. If you wish to change the values to correlate with
another blood gas analyzer, you must use the following procedure:
1. The correlation factors in the 248 must be reset to:
pH,
p CO
2
and p O
2
slope = 1.000
pH, p CO
2
and p O
2
intercept = 0.000
2. Use a large sample population covering the physiological range –
minimum 50 samples, preferably 100 – to generate a random
distribution of values (not just normal values).
3. Make sure that the 248 and the reference analyzer are calibrated
following the manufacturer’s instructions, and are operating within
specifications.
4. Samples should be stored iced, and measured within 30 minutes of
collection. Samples should be analyzed in duplicate on both
analyzers, with no more than 5 minutes between analysis on the
248 and analysis on the reference analyzer.
5. Remove outliers from the data (means of duplicates values outside
± 3SD, or duplicates which differ).