15
MAIN
This
mode defaults on power up, with
mass flow as the primary displayed
parameter.
The following parameters are displayed in
the Main mode.
Gas Absolute Pressure:
This sensor
references hard vacuum and reads
incoming pressure both above and below
local atmospheric pressure. This parameter
is moved to the primary display by pushing
the button above
PSIA
. Pushing this button
again shows unit changes.
The engineering unit associated with
absolute pressure is pounds per square
inch absolute (psia). This can be converted
to gage pressure (psig) by subtracting local atmospheric pressure from the
absolute pressure reading:
PSIG = PSIA – (Local Atmospheric Pressure)
Gas Temperature:
MC-Series flow
controllers measure the incoming
temperature of the gas flow. The
temperature is displayed in degrees
Celsius (°C). This parameter is moved to
the primary display by pushing the button
above
°C
.
Pushing the button again allows you to
select 0C (Celsius), K (Kelvin), 0F (Fahrenheit)
or 0R (Rankine) for the temperature scale.
To select a temperature scale, use the UP
and DOWN buttons to position the arrow in
front of the desired scale.
Press SET to record your selection and
return to the MAIN display. The selected
temperature scale will be displayed on the screen.
Set Point
:
The set-point (
SETPT
)is shown in the upper right of the display.
For information on changing the set-point see SETPT SOURCE, page 18.
Volumetric Flow Rate:
This parameter is located in the lower left of the display.
It is moved to the primary display by pushing the button below
CCM
in this
example. Your display may show a different unit of measure. Pushing this button
again shows unit changes.
#C
+21.50
+0.00
CCM
MENU/
TOTAL
SETPT
+0.00
SCCM
Air
PSIA
+13.60
+0.00
SCCM
DOWN
CANCEL
SET
>#C
K
#F
#R
UP
+0.00
When using a mass flow controller as an absolute pressure
controller
, the mass flow rate may momentarily exceed the flow
measurement capability (full scale + 28%) of the unit. This may
occur when the unit is asked to make an abrupt pressure change.
If the optional totalizer is in use at that time
, the totalized value
will necessarily become incorrect. Please reset the totalizer if such an
‘over-flow’ condition has occurred.
Mass Flow
