Page 5-4 248 Operator’s Manual
Adjusting Correlation
6. Perform a linear regression analysis. We recommend the Deming
method, which accounts for errors on both axes. The linear
regression should be performed using a regression program on a
calculator or computer. The 248 should be treated as the dependent
variable (Y-axis), or the variable on the left hand side of the
equation.
NOTE: The X variable should be the reference analyzer.
7. The intercept and slope values obtained can then be entered using
the Correlation routine.
NOTE: Values can only be entered into the Correlation routine in pH
units and mmHg. If you use H
+
nmol/L or kPa for measurement, these
values must be converted into pH units and mmHg before entering.
To convert from H
+
nmol/L to pH:
pH = 9.0 - log
10
(H
+
nmol/L)
To convert to mmHg from kPa:
mmHg = kPa x 7.50062
To adjust the correlation: from Ready press # for menu, 5 for
Operating Setup and 6 for Correlation.
Default setting: pH, pCO
2
, pO
2
slope = 1.000
pH, pCO
2
, pO
2
intercept = 0.000
System Setup
From Ready press # for menu and 6 for System Setup.
Changing Date and Time
The 248 shows the time and date of calibrations and measurements on
the printout.
To change the date and time: from Ready press # for menu, 6 for
System Setup and 1 for Date and Time.
Default setting: Date and time set.
Main Menu → System Setup
1 Date and Time 5 Communications
2 Maintenance Prompt 6 Security
3 Parameters 7 Print Setup Report
4 Beeper
press 1 - 7 or * to Exit
To Next Page
Loading...
Need help?
General
