Page 25 of 34
SUPER SESI, by FIT
User manual, Revision 2.0
through the EXHAUST fitting, and a third part goes to the Sample Line, to clean it and
avoid entering contamination when no sample is introduced. The clean gas now is
adjusted.
For adjusting the Sample Gas Flow, choose your setpoint value at the MFC: it will be the result
of the sum of the measured clean gas (step 3) with the sample gas flow that you need to enter
the ionization region (this flow depends on the application).
This fine control of the sample gas flow helps with the standardization when introducing
samples: always the same sample flow enters the ionization region.
EXAMPLE
After obtaining a 0.35 LPM clean gas flow value in step 3 and knowing that
my analysis acquisitions require 0.2 LPM at most, I will fix a setpoint of 0.55 (0.35 + 0.2
= 0.55 LPM)
TIPS & TRICKS
. In order to select an optimum sample gas flow for your application is
recommended to try some acquisitions and select the most effective one.
INTERESTING NOTE
Taring your Mass Flow Controller is an important practice that ensures that
it is providing the most accurate measurements possible. This function gives the flow
controller a good zero reference for flow measurements. Taring can also be used to align
the internal absolute pressure sensor with the barometric pressure reading.
When auto tare is -
ON
- your flow controller automatically tares its flow rate whenever it has a
zero setpoint for more than 1.2 seconds. For manual tares, follow these steps:
1.
Ensure that nothing is flowing through the device, usually by giving the controller a zero
setpoint.
2.
MENU→TARE→TARE FLOW
. Flow tares should occur at the expected process pressure,
as long as there is no flow.
3.
MENU→TARE→TARE PRESS
. Absolute pressure tares must be done with the controller
open to atmosphere.
When to tare:
•
After significant changes in temperature or barometric pressure.
•
After dropping or bumping the flow controller.
•
After installing the controller in a different orientation.
Starting the electrospray
INTERESTING NOTE
Before you can start the electrospray, the SUPER SESI must be properly
coupled with the mass spectrometer, the temperatures must be stable, the flows must
also be stable and the mass spectrometer must identify the ion source.
Position the electrospray tip at a distance of 0 to 8 mm from the inlet capillary of the mass
spectrometer. For this, unlock the capillary positioner lock, slide the positioner until the
positioner mark is at the desired distance, and lock the positioner in the new position. The
distance between the tip of the silica capillary and the inlet capillary of the MS is marked in the
electrospray probe handgrip.
