10
Gas Tank Connections Tools required: 7/16” wrench (not supplied).
Attach a dual stage gas regulator to a cylinder of analysis gas, usually ultra-high purity helium or
nitrogen. Connect the output of the regulator to the compression fitting on the right side of the
cabinet using the 1/8” copper tubing and nut & ferrule set supplied.
Do not use plastic tubing. If you need to extend the gas supply line always use clean copper (or
stainless steel) tubing with appropriate metal compression fittings.
It will be necessary to obtain an adapter to connect the tubing to the regulator if it does not have a
1/8” Swagelok® brand fitting. A suitable regulator assembly (P/N 01207) complete with shut-off
valve, CGA580 cylinder connector and 1/8” Swagelok® brand outlet fitting is available from
Quantachrome.
Adjust the pressure regulator to slightly above 20 psig (140 kPa).
Pressures above 25 psig could
potentially damage the MULTIPYCNOMETER’s pressure transducer.
Check all connections for leaks using soap solution.
Sample Cells and Sample Cell Holder
Three sample cells (stainless steel cups) and two adapter sleeves are supplied with the
MULTIPYCNOMETER. Sample cells are placed in the chamber with the screw cap - the
sample
cell holder
. To open the sample cell holder, rotate the cap’s outer ring counter-clockwise until it can
be lifted off. To remove the sample cell insert the lift out tool into one of the holes near the top of the
cell and lift it out of the holder.
Sample cells should be removed from the unit before being filled with sample or adding calibration
spheres. Use the largest amount of sample available for best accuracy. If you do not have enough
sample material to fill the large cell (135 cm
3
) to at least 50% of its volume, use the small cell (20
cm
3
) and the micro cell (4.5 cm
3
) for even smaller quantities. The small and micro cells are always
used with the appropriate adapter sleeve.
When calibrating a cell, especially the large cell, do not simply drop the large sphere into the cell but
turn the cell sideways and roll the sphere into it to prevent deforming the cell.
When using the large sample cell, ensure that the horizontal slit(s) near the top of the cell line up
with the vertical groove(s) machined into the cell holder. This ensures that the gas has a free path
into and out of the cell.
Before replacing the cell holder cap make sure that its O-ring
1
is undamaged, clean, lightly greased
2
and is secured in the groove inside the cap. Align the fiduciary mark on the cap with the line on the
cabinet ring; a locating pin on the bottom side of the cap slots into a hole in the top edge of the
sample cell holder. Then rotate the outer ring of the cap clockwise (on the threads of the cell holder)
until metal to metal contact is made.
1 Spare O-rings are sold in packs of two, p/n 51000-032.
2 Use Vacuum Grease P/N 91000-.25 to lubricate O-ring, never petrolatum.