NEW BRUNSWICK SCIENTIFIC BioFlo 4500, Manual To Operations

Page: 134 / 214

BioFlo 4500 M1254-0050 User’s Guide
134
17.1.2 Sparging with Nitrogen to Calibrate DO Zero Point
A more accurate zero setting is obtained by assuring the probe has
stabilized at the desired growth temperature and then by setting agitation
speed to 500 rpm and sparging nitrogen into the vessel. After the DO
reading stabilizes for at least 5 minutes, enter the “zero” on the
PROBE
CALIBRATION SCREEN
.
To calibrate the span:
To calibrate the span value, the fermentor should be on and operating at
the desired growth temperature. Then proceed as follows:
•
Set the agitation speed to 500 rpm and vigorously sparge air into the
vessel.
•
Carefully monitor the current value reading of DO control loop display
gauge. Once the reading has stabilized, press the
CAL BUTTON
. The
CALIBRATION SELECTION WINDOW
will appear.
•
Select the DO control loop from the list by pressing on it. The
LOOP
CAILBRATION SCREEN
will appear.
•
To set the span, ensure that the
SET SPAN FUNCTION
is selected, and
enter 100 into the span text box using the onscreen keyboard. Once
the number is entered, press the
SET SPAN
button. The value entered
will then become the span value.
•
Press
CLOSE
to exit this window.
NOTE:
The probe is calibrated in percentage air saturation at a given
temperature, a given pressure (calibration conditions). If pressure is
raised, then readings may be obtained which are higher than 100%.
NOTE:
Monitoring DO during calibration can be done by viewing the DO
gauge or by setting up a Trend Graph for DO and viewing the graph.
(See section on Creating a Trend Graph) .