Global Water GL500-7-2 Manual page 23

Global Water
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The calibration of channel one to a pH sensor is discussed in the following example
where it is not practical to calibrate a sensor over its full range. The pH sensor is
measures over the range of zero to 14 but is generally calibrated over a lesser range
such as 4 and 10 even when it is desirable to measure beyond these limits.
Enable: If the "Enable" box at the top of a column is checked,
data for that channel will be shown in the historical record and
be available for export to Excel. The data
for all the analog channels is always being
recorded whether the channel is enabled
or not.
Units: This field shows the units that will
appear at the top of the data column for
that channel in the historical record as well
as the display of data in the main screen.
Click on the field to enter the unit or select
from a predefined list.
High EU: The High EU field is the engineering unit where the
highest output from the sensor is achieved during the calibration process, in this
case a pH of 10.
Low EU: The Low EU field is the engineering unit where the lowest output from the
sensor is achieved during the calibration process, in this case a pH of 4.
High Raw: This is the raw data value as measured by the GL500 Data Logger that
corresponds to the High EU value and is automatically set by the calibration process.
In this case, the raw data value returned by the logger at a pH of 10.
Low Raw: This is the raw data value as measured by the logger that corresponds to
the Low EU value and is automatically set by the calibration process. In this case,
the raw data value returned by the logger at a pH of 4.
Disp High: This field sets the upper limit of the bar graph displayed in the main
screen and provides a way of scaling the graph beyond the upper limit used to
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