Meter Setup Menu Features
Automatic Calibration
The Orion Star and Star Plus conductivity meters are capable of automatically
recognizing 100 µS/cm, 1413 µS/cm and 12 .9 mS/cm conductivity standards when
the nominal cell constant of the conductivity probe is entered in the setup menu .
For the meter to recognize the conductivity standard, the entered cell constant must
be accurate within a factor of 3 . For example, if the actual cell constant is 1 .0 cm
,
-1
entering a nominal cell constant in the range of 0 .3 cm
to 3 .0 cm
would allow the
-1
-1
meter to identify the conductivity standard and perform the automatic calibration .
SE Setup Menu Features
Concentration Range
The Orion Star and Star Plus 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 .
Automatic Blank Correction
The Orion Star and Star Plus ISE meters have an ISE automatic blank correction
feature that uses an algorithm to compensate for the non-linearity of the ion
selective electrode in low-level standards and samples . Since the automatic blank
correction feature requires the use of a set of non-linear equations that can only
be calculated numerically, the user cannot analytically verify the calibration and the
average slope value that is displayed on the meter may be outside of the slope
range that is specified in the electrode user guide . In applications were analytical
verification is required, the automatic blank correction feature should be turned off .
EN-68
Thermo Scientific Orion Star
and Star Plus Series Meter User Guide
™