Sabio 2010D, Operation Manual

Page: 140 / 182

Internal Calibrations Page 8-7
The columns of data entered into this screen are:
Control
This column of numbers represents the
control voltage to the mass flow
controller.
Monitor
This column represents the voltage
output of the mass flow controller when
it has stabilized after the control
voltage has been applied. The monitor
voltage should normally be very close to
the control voltage.
Flow
The flow column represents the actual
flow, as measured by an external flow
standard, through the flow controller
when it has stabilized after the control
voltage has been applied.
By pressing the F7 key while a number within a column is
highlighted, that column’s units of measure can be changed; for
example allowing voltages to be entered in units of Volts or mV
and flows to be entered in SCCM or SLPM. Although the data may
be entered in different units, any coefficients or linearization
equations calculated from the table will be in terms of Volts (X)
and SCCM (Y).
Once the data table has been entered, pressing the ESC key will
cause a dialog box to appear, asking if you want to calculate the
coefficients. Answering "yes" to this dialog causes the
coefficients to be calculated and, if the linearization method is
linear or polynomial, presented for review. One particular item
to note at this point is the correlation. For mass flow
controllers, the correlation should be very close to 1.0000,
indicating a very close correlation to a straight line. The
ozone generator, being slightly non-linear prior to calibration,
will not normally correlate as closely to a straight line as an
MFC. If everything looks good, answering "yes" again causes the
changes to be saved.