GE Xcellerex XDM Series Operating Instructions Manual page 161

If the calibration fails, find the cause of the failure using the transmitter and sensor user
manuals.
Tip:
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:
•
•
•
Follow the instructions below to perform the pH probe standardization.
Step
1
2
3
Xcellerex XDM 50-1000, XDUO 100-1000 mixers Operating Instructions 29251615 AD
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, respectively.
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 10.8 Temperature probe
calibration, on page 289 for instructions.
Action
Take a sample of the disposable bag contents, using the sample tubing. See
Illustrations of the Plus bag assembly, on page 79 for information of the bag
tubing.
Measure the pH of your sample using an external calibrated pH meter.
Perform the standardization as follows, using the pH/DO transmitter display
on the I/O Cabinet:
6 Preparation
6.4 Prepare and install the probes
6.4.1 Calibrate the pH probe
161