Thermo Scientific Orion Star User Manual page 65

pH Troubleshooting
Problem: The meter does not recognize the pH buffer value during calibration .
Solution: Verify that the correct buffer set was selected in the setup menu .
The meter uses the raw mV reading of the electrode to recognize
a buffer during calibration . As the electrode ages or becomes dirty,
its mV readings will drift and you will need to manually enter the
pH buffer value when calibrating .
ISE Troubleshooting
Problem:
It takes several minutes for the readings to stabilize during a calibration .
Solution: The concentration range in the setup menu is set to low . Change the
concentration range to high . The ISE resolution is set to 3 digits in the
setup menu . Change the ISE resolution to 2 digits for faster stabilization
of the readings .
Problem: When I use the automatic blank correction setting and calibrate an ISE,
the meter gives a slope that is too low or cannot be manually checked .
Solution: Turn the automatic blank correction setting off in the setup menu .
Conductivity Troubleshooting
Problem: The meter does not recognize the conductivity standard during
calibration .
Solution: Verify that the default cell constant was entered in the setup menu .
The cell constant is usually printed on the conductivity probe cable .
Verify that the conductivity standard is one that is programmed into
the meter . Re-calibrate with a fresh standard .
Problem: The temperature coefficient value does not appear in the setup menu .
Solution: The current temperature compensation setting is nonlinear or off .
Change the temperature compensation to linear and the next screen
will be the temperature coefficient value entry screen .
Problem: The measurement is out of range when it should be in range .
Solution: Check that the conductivity probe is fully immersed in the solution .
Verify that the cell constant is correct for the conductivity probe that
is connected to the meter . Verify that the cell type selected in the setup
menu is set to Std .
Thermo Scientific Orion Star and Star Plus Meter User Guide
™
Troubleshooting
EN-59