Marconi Instruments 933D Instruction Manual page 10

Unscrew the clamp. Withdraw the test cell. Take out the plunger.
(1)
See that the insulating ring is well seated on the electrode with its open end upwards. In
(2)
handling the electrode, hold by the edges.
moisture on the insulating surface between the
(a) For whole grains put enough into the test cell to form a single layer.
(3)
(b) For ground samples half fill the test cell with meal. After the test the compressed
plug should be about 1/16 inch. Ensure that the sample is lying uniformly in the bottom of the
test cell; a gentle shake will ensure this in most cases.
Insert the plunger and hold it down (to prevent the sample slipping to one side) then slide
(4)
the complete test cell into the clamp.
Screw the clamp down until the two parts of the cylindrical spring housing, mounted on
(5)
the end of the screw, become flush.
The spring is compressed solid by about a half turn of the screw beyond
CAUTION
standard thrust at which tests are made. The solid point can easily be felt on the
tommy-bar. DO NOT ATTEMPT to tighten beyond this point as it is possible
for a strong operator to strain the clamp.
Take electrode (A)
Add ring (B)
Half fill the cavity
then add plunger (C)
Screw the assembly down in
the clamp until flush at (D)
(A)
46882-171 D
Apr. 92
Do not handle the upper surface as this may deposit
two electrode rings.
(C)
(B)
Fig. 2.1 Compression cell electrode assembly
(D)
OPERATION
9