7.2 Replacing the Dip Tube and Splash Plate

Powder-free nitrile gloves should be worn at all times to avoid contaminating the Lonestar sample flowpath.  Set the gas purge to ON in the Lonestar software, wait for 10 seconds and then turn off the gas flow to the Lonestar system.  Allow the Lonestar pressure to drop below 0.4bar_g before unscrewing the bottle holder from the heated lid to expose the dip tube.

 

Removing sample holder

Using a ¼” spanner, undo the dip tube from the heated lid.  The splash plate is held captive on the dip tube and will be removed at the same time. 

 

Removing the dip tube

Assemble the splash plate and dip tube by screwing the dip tube through the larger hole in the splash plate.

Splash guard and dip tube	Mount splash guard

  

Slide an Allen key or narrow screwdriver through the smaller hole in the splash plate.

Align dip tube with flowpath exit

Use the Allen key to locate the exit flow path through the heated lid.  This also keeps the splash plate horizontal to ensure it passes cleanly into the recess in the heated lid.  Locate the screw thread in the heated lid for the dip tube and screw the dip tube into the heated lid.

Inserting dip tube

Once the dip tube is snugly tightened into the heated lid, push up against the underside of the splash plate to ensure it is correctly seated in the recess in the heated lid.  Tighten the dip tube into the heated lid using a ¼” spanner.

Tighten Dip tube

A blank sample bottle should be placed in the bottle holder and screwed into the heated lid until snug.  The carrier gas flow should be restored to the Lonestar system, waiting for the pressure to build before turning the gas purge OFF.  Collect a few DF matrices, scanning from 0% to 100% dispersion field to ensure the dip tube and splash plate are not contaminated; this also allows the dip tube and splash plate to reach their operating temperatures, being heated from the heated lid.