If the calibration fails, find the cause of the failure using the transmitter and sensor user
manuals.
If duplicate probes are used, label the calibrated probe as pH-1. Then repeat the steps
described above to calibrate the second pH probe and label it as pH-2. After sterilization
the probes need to be connected to pH/DO transmitters pH/DO-1 and pH/DO-2, respec-
tively.
Standardize the probe (offset at
reference pH)
For the greatest possible accuracy a standardization procedure must be performed. You
need a sample of the contents of the disposable bag. Perform this procedure when the
probes have been installed in the disposable bag.
Make sure that the following has been completed before pH probe standardization:
•
The disposable bag has been filled.
•
The contents of the disposable bag have been equilibrated to the process tempera-
ture.
•
The temperature probe has been calibrated. See
Section 10.5 Temperature probe
for instructions.
Follow the instructions below to perform the pH probe standardization.
Action
Step
Take a sample of the disposable bag contents, using the sample tubing. See
Illustrations of the bag assembly, on page 81
for information of the bag
tubing.
1
Measure the pH of your sample using an external calibrated pH meter.
2
Perform the standardization as follows, using the pH/DO transmitter display
on the transmitter cabinet:
3
Xcellerex XDUO 2500 Mixer Operating Instructions 29146667 AH
179
6 Preparation
6.4 Prepare and install the probes
6.4.1 Calibrate the pH probe
