Back Pressure Coils For The Dionex Crs 500 - Thermo Scientific Dionex Chemically Regenerated Suppressor 500 Series Product Manual

2 – Installation
! During the course of installing and using the Dionex CRS 500, it may be necessary to
assemble 1/4-28 or 10-32 ferrule/bolt style liquid lines. See, "Dionex Liquid Line Fittings,"
for complete details.
NOTE

2.2 Back Pressure Coils for the Dionex CRS 500

All detector cells require enough back pressure to prevent eluent in the cell from out-gassing
due to abrupt volume changes between the small inner diameter of the connecting tube and the
relatively larger volume of the cell. Out-gassing creates bubbles in the cell and disrupts detector
responsiveness. Back pressure coils help to prevent gases from out-gassing and prevents
formation of bubbles in the detector cell. For example, carbonate eluent is suppressed to
carbonic acid which is CO
if adequate pressure is not applied. The above out-gassing can trap bubbles in the cell causing
high noise. Therefore Dionex recommends addition of 30-40 psi of backpressure for most
applications.
Back pressure coil components are located in the detector Ship Kits as part of the Gas Separator
Waste Tube Assembly/Back Pressure Coils Kit, P/N 045825. For 4 mm systems, locate
assembly P/N 045877. For 2 mm systems, the backpressure coils are available in the microbore
tubing kit, P/N 052324. For 2 mm systems, locate assembly P/N 045878. Alternatively, lengths
and diameters of tubing necessary for proper back pressure are given in Table 2, "Coils for
Dionex CRS 500 Back Pressure Requirements."
backpressure of approximately 40 psi.
!
If back pressure coils become damaged or plugged, they may cause irreversible damage to
the suppressor.
CAUTION
Assemble as follows:
A. Slip PEEK liquid line bolts and ferrules onto the ends of the tubing. Refer to Table 2,
B. After assembly of the coils, see Figure 8, "Configuration of the External Chemical
Thermo Scientific
031727-07
gas in equilibrium with DI water; CO
2
"Coils for Dionex CRS 500 Back Pressure Requirements," and determine the correct
number of coils required for your application based on the eluent flow rate.
Mode with the Dionex CRS 500 Suppressor," for the proper placement of the
assembled coils and couplers after the detector cell and before the waste container.
Product Manual for Dionex CRS 500 Suppressor
gas can come out of solution
2
Adjust the tubing length to achieve a
Page 19 of 40