Metrohm 828 IC Dual Suppressor - Manual (Page 32)

3 Operation
828 IC Dual Suppressor/ 8.828.1003 Instructions for Use
24
removed and the equilibrium for the breakdown of the carbonic acid is
displaced even further toward the dissociated products. The CO
2
absorber cartridge is required to remove CO
2
and humidity from the
drawn-in ambient air before it enters the degassing system. Exchanging
the CO
2
absorber cartridge is described in Section 5.4.1.
The vacuum pump works at a constant speed and as soon as the
vacuum reaches the preset working pressure LED "Vacuum" 5 lights up
green.
3.5 Flow rate ratio
Please ensure that the backpressure capillary is mounted at the outlet
of the detector used, see Section 2.4.2, Section 2.5.2; it is required for
the correct ratio between the flow rates.
Check this ratio between the flow rates before starting up the 828 IC
Dual Suppressor for the first time.
The 828 IC Dual Suppressor achieves its optimal performance when
40% of the total flow is eluted to the detector. The 828 IC Dual
Suppressor is preadjusted for a total flow rate of 1 mL/min. At a total
flow rate in the working range of 0.5 - 2.0 mL/min this flow ratio only
changes slightly, but you should nevertheless check it when you alter
the total flow rate.
If more than one detector is used in series downstream the IC Dual
Suppressor then the ratio between the flow rates must be adjusted in
order to compensate for the additional backpressures of the other
detectors.
3.5.1 Setting the flow rates
The IC Dual Suppressor is designed to work at a flow rate to the
detector of 40% ± 5% of a total flow rate of 1 mL/min.
The following instructions describe in detail how you can check the ratio
between the flow rates and alter it if necessary:
1 Preparation
Set the flow rate at the pump to 1 mL/min and wait for 10 minutes.
2 Measurement
Measure the volume V or the weight m of the liquid which elutes
from the backpressure capillary in 3 minutes.