DTC-300 Getting Started Guide
Page 33
5
As the plate is pushed down, excess sample material is expelled from the cell through the small bleed
holes. Remove the excess sample material.
NOTE
: If the top surface of the metal plate ends up below the top of the outer ring, you have chosen the
wrong outer ring. The top metal surface must always be above the outer ring.
6
Hold the cell by the outer ring and apply thermal compound to the exposed top and bottom metal surfaces.
7
Place the cell on the bottom plate of the DTC-300.
8
The specimen thickness entered under "Sample Information" of the DTC-300 operating program is the
thickness of the spacer measured in step 1 above. Be sure that the calibration selected for testing with
the paste cell is one obtained with the cell in the test chamber and not one for testing solid specimens
without the cell.
Polymer Melt Cell Testing
The polymer melt cell is used to test a polymeric material from a solid through a molten/semi-molten state.
The cell is comprised of several components, which when assembled will contain the molten polymer, pre-
venting damage to the instrument. The maximum temperature of use is 300ºC.
Loading a Sample into the Polymer Melt Cell
The polymer melt cell incorporates 6 parts: the cell containment ring, two consumable split seal rings, an
inner spacer ring (also a consumable part), and both a top and a bottom plate.
The top and bottom plates are made of a stainless steel alloy to prevent any contamination of/interaction
with the specimen being tested. The faces of the plates will be in direct contact with the specimen and also
with the stack assemblies of the conductivity meter. Any scratches or gouges in the surfaces can lead to a
decreased accuracy of the results. These parts are re-usable.
The split rings and the inner spacer ring are made from a dense insulation material. They are fragile, and
must be treated with care. They can be re-used with some care, but are considered consumable and may
require replacement after testing. Inspect each part to guarantee the channels in the split rings and the
grooves in the spacer rings do not show any signs of damage prior to loading the cell. They are low con-
ductive materials to prevent any radial heat issues from developing during the test.
The outer containment ring is used to hold the entire assembly together. It is made from an aluminum alloy,
and can be used repeatedly. The split rings are a snug fit inside the containment ring, so exercise caution
when sliding them inside.
1
Begin with the outer containment ring. Place it with the lip on the bottom.
2
Next, locate the two split seal rings. The top of the rings is machined flat, while the bottom of the rings
has an offset shoulder machined into the insulation. Place the rings together, and carefully insert them
into the outer containment ring.
3
The bottom shoulder should align with the inside of the lip on the containment ring, and should not
extend beyond the ring; it should be flush with the bottom of the containment ring. Carefully press down
on the split rings to seat them in the containment ring. Once the split rings are in place, take the split
ring assembly and place it onto the bottom plate. The bottom plate has a groove milled into the face.
The groove must point upwards. The groove is used to properly position the inner spacer ring.
4
Gently press down on the split rings to seat the bottom plate. The bottom plate will extend approximately
1/8" (3 mm) below the bottom of the split rings.
