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,
p
CO
2
,
p
O
2
slope = 1.000
pH,
p
CO
2
,
p
O
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
Summary of Contents for RAPIDLAB 248
Page 1: ...248 91 001N Rev T 2008 04 Operator s Manual ...
Page 24: ......
Page 96: ......
Page 104: ......
Page 118: ......