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Thermo Scientific Orion Star LogR™ Meter User Guide
Appendix A
Meter Setup Menu Features
pH Setup Menu Features
Automatic buffer recognition
The Orion Star LogR pH and pH/ISE meters are capable of automatically recognizing
pH 1.68, 4.01, 6.86, 7.00, 9.18, 10.01 and 12.46 buffers during a pH calibration.
During a calibration, the meter uses the selected buffer set and the raw mV reading
of the pH electrode in the buffer to recognize and display the buffer value at the
measured temperature. The raw mV value must be about ± 30 mV from the
theoretical mV reading of the buffer in order for the meter to automatically recognize
the buffer.
Buffer
mV Range
Buffer
mV Range
Buffer
mV Range
1.68
+285 to +345
7.00
- 30 to + 30
10.01
-207 to -147
4.01
+207 to +147
9.18
-99 to -159
12.46
-293 to -353
6.86
+38 to -22
ISE Setup Menu Features
Concentration Range
The Orion Star LogR pH/ISE meters can be set for a high or low ISE concentration
range that is used to determine the calibration stability criteria. If a high ISE
concentration range is selected, the meter will perform a normal calibration with
no delay in displaying the calibration standard value. If a low ISE concentration
range is selected, the meter will wait about three to five minutes before displaying
a stable reading for the calibration standard values. The delay will depend on the
species being measured and the concentration of the calibration standards. The low
ISE concentration range is designed to improve the accuracy of low concentration
measurements by allowing the electrode to have a longer amount of time to
stabilize in the calibration standards.
