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CONNECTIONS
Vertical Displacement Rod – Screws into the top plat-
form to the right of the rear pull-down rod.
Vertical Displacement Clamping Arm – Attach to the
above rod.
Vertical Displacement Dial Gauge – Consolidation –
Attach to the clamping arm with the screw provided.
Horizontal Displacement Dial Gauge – Shear – At-
tach to the threaded rod on the angle bracket-top plat-
form, right front.
Air Line – A constant supply of air is required. The air
inlet air pressure should not exceed 200 psi, nor should
it ever be less than 20 psi higher than the highest pres-
sure setting. The connection is a ¼" Swagelok, located
in the rear of the cabinet. Insert the tubing into the fit-
ting until it bottoms out. With the nut finger tight, tighten
the fitting 1 ¼ turns with a wrench. Do not over tighten.
Load Cell – Connect the load cell to the support cast-
ing at the right end of the direct shear using the two
knobs. Adjust the knobs so that the load cell is as far
to the right as possible. This will allow room for assem-
bling the water chamber and the shear rings with min-
imum interference. Connection is made at the rear of
the readout cabinet.
Water Chamber – Special care should be taken to
see that the four (4) roller bearings between the water
chamber and the base slide tracks are properly cleaned
and contain a slight amount of oil during and after use.
We advise using a cover over the direct shear after
use to eliminate dust from entering the precision slide
assembly. The main drive shaft should be at its home
position. This will place the sample load pad in the cen-
ter of the crossarm for consolidation.
Shear Boxes (sold separately) – The shear boxes
are held together with (2) stainless steel screws. There
are also (4) screws for adjusting the gap between the
rings once consolidation has been reached. The gap
is adjusted by turning the screws clockwise from the
finger tight position. One full turn will give .031" gap.
There is a line scribed on the adjusting knob for deter-
mining how much gap each screw has provided. The
screws should be turned evenly to maintain a proper
gap. At the bottom of each screw is a nylon glide which
keeps the top shear ring from dropping during the test.
FRONT PANEL CONTROLS
The consolidation load settings and strain rates
are
controlled
from
the
front
panel.
Machine
must be plugged in to a properly wired ground-
ed receptable with appropriate electrical current.
PANEL CONTROLS — LOAD SETTING
Residual Shear Force LCD Readout – The digital
readout will display real time load settings and peak
load of the horizontal load cell. Use the tare button to
zero the display before starting test.
Load Regulator – A precision Fairchild regulator is
used to set and maintain the air pressure to the pis-
tons which provides load to the sample. The regulator
is sensitive to 1/8" variations in water column. Select
the load required from the load setting table.
Note: The consolidation load pad, porous stone, and
stainless-steel ball have not been included in the load
setting calibrations.
High Load/Low Load Selector Valve – This valve
has two positions. The LOW LOAD position is used for
loads up to 100lbs depending on the model. The HIGH
LOAD position is used for loads up to 1500lbs.
Load Valve – This valve is actuated by 90-degree ro-
tation of the handle. When open it allows air to flow
from the regulator to the pistons (HIGH or LOW LOAD)
selected.
PANEL CONTROLS — POWER & SHEAR RATE
Power Switch – An indicator light is present when
power is turned on.
Strain Rate Selector – The strain rate is set with
thumbwheel selectors. The switches are direct reading
in inches/minute with an implied leading decimal point.
Once the rate is set and the test is started, the switch
setting is ignored until the stop switch is pressed or a
limit switch is tripped.
Limit Switches – These switches are located on the
platform behind the water chamber.
Adjustment of these switches is made by loosening the
Phillips-head screws and moving the limit switch as-
sembly in the direction desired. The home position has
been set so that the load crossarm is in the middle of
the shear rings.
Note: The limit of travel of the drive shaft is dependent
on the limit switch settings. Do not operate the drive
motor with the water chamber disconnected because
this will make the limit switches inoperable.
2
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