Temperature Control
Oven temperature calibration
The HP 5890 provides the means to (if necessary) reset oven temperature monitoring so the displayed ACTUAL value accurately represents the correct temperature.
Oven temperature calibration requires entering the difference (delta) value (in ^C) between an independently measured temperature value versus the corresponding displayed oven temperature value:
Correction Value =
Measured Temperature (^C) - Displayed Temperature (^C)
For example, if actual measured oven temperature were found to be 148.73^C, while the corresponding displayed value was 150.00, the calibration difference value to be entered would be
Setting the oven calibration value
An oven temperature calibration measurement should be made at a temperature in the middle of the range of interest. Allow ample time (up to 1/2•hour)for thermal equilibration at the selected temperature; no drift should be observed. The temperature•sensingprobe should be placed in the region of the oven occupied by the column(s).
1. Through the keyboard, select CALIB AND TEST mode, function 1:
CLEAR
.
1 
ENTER
CALIB is displayed, followed by two values: the observed oven temperature (to 0.01^C), and the current difference (delta) calibration value.
Note: Record the displayed calibration delta value! If problems are encountered in recalibration, the value may be reentered.
2.Assuming no drift in temperature, the new difference (delta) value is then entered by pressing appropriate number keys, followed by 
ENTER
:
appropriate value 
ENTER
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