Fluigent FLOW UNIT User Manual page 15

Calibration method: Example with FC40 oil calibration
A method for providing a known flow-rate is required to work out
the scale factor for the selected fluid. This could be a syringe pump,
a peristaltic pump or a pressure regulator delivering fluid onto a
precision balance with volume calculated from known density.
Here is an example using Flow EZ
flow controller delivered by FLUIGENT. The aim of this FASTAB
technology is to pressurize a reservoir containing the fluid of interest
to be injected through the microfluidic system.
Make a table that contains the time for each measurement, the
flow-rate of the pump and the data measured by the FLOW UNIT.
A minimum of 3 measurements is recommended for each flow-rate.
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DUAL CALIBRATION
TM , a fast and stable pressure-based
DUAL CALIBRATION
The principle of the experiment is to inject the desired fluids, here
it's FC-40, through the desired FLOW UNIT model connected to the
FlowEZ. Then simultaneously you record the flow-rate given by the
software and you measure the weight of fluid you have collected over
a chosen period of time. Knowing the density of the fluid, you are able
to define the actual flow-rate.
Note that if a peristaltic or a syringe pump is used, one has to
wait until the target flow- rate is reached (settling times can be
TM
long) and to calculate an average flow-rate due to the pulsations.
The list of materials needed to reproduce the experiment is given
below:
One (1)FLOW EZ
One (1) FLOW UNIT model
One (1) precision weighing scale
The table below displays the information recorded during the
experiment: the pressure imposed by the MFCS™- EZ, Qs the flow-
rate recorded by the FLOW UNIT through the Flow- Rate Platform
software, Qw the flow-rate measured with the precision weighing
scale, and Qw/Qs the calculated scale factor for a single point
calibration.
Pressure (mbar)
596.3
Consequently, when working around 317 µl/min (target flow-rate), you
have to add the scale factor of 3.5 so that the measurement of the
sensor corresponds to the actual flow-rate for FC-40.
Q (µl/min) Q (µl/min)
S W
91.6 317.8
Q / Q
W S
3.5
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