Humboldt H-1240D.4F Digital Penetrometer with Digital Automatic Timer - Manual (Page 3)

Introduction
The Humboldt Digital Penetrometer with Automatic Digital Timer is of rugged
construction, but requires careful handling to safeguard its accuracy. Keep the
instrument clean at all times – especially the drop and indicator plungers, which
constitute the spindle assembly. Use denatured alcohol as the cleaner for these
surfaces.
For complete test procedure(s), refer to the following specifications: ASTM D5,
D217, D937, D1168, D1321, D1403, D1831, and AASHTO T49.
Installation
1. Level the instrument carefully by means of the leveling screws on the base,
sighting the spirit level from above, in order to obtain accurate alignment.
After the instrument has been leveled, avoid shifting its location.
2. Position the height of the supporting casting by turning the knurled travel
nut on the main support post and then tighten the black knob.
3. If additional weights are used, these should be taken from the side post and
set on the end of the plunger (opposite end of the needle chuck).
4. Insert penetrating needle or cone into chuck and tighten the chuck screw.
Instruction
As supplied by Humboldt the unit is programmed to provide a solenoid
actuation period (plunger release) of 5 seconds. The panel-mounted, electronic
timer uses 120 VAC, 50/60 Hz. In order to use 240 VAC, a step-down transformer
or converter suitable for digital circuits is required. The H-1240D.4F is supplied
with an H-1042 transformer for this purpose and is plug compatible with the
penetrometer cap-plug, but requires the input line cord to the transformer to be
wired for local service.
For further timer information refer to the ATC Model 365B Long Range Timer
Instructions.
Operation
1. Holding the plunger with one hand, squeeze the lever on the front of the
support casting with the other to allow raising the plunger & needle to clear
the sample. Flip the toggle switch on the front panel to the up position and
pre-select the specified time of penetration by turning the knobs on the
timer bezel.
2. To conduct a test set the needle, cone or micro-cone using the shadow of
its tip to just meet the sample surface, and then lower the indicator spindle
to rest on the top of the plunger. Press the indicator ON/clr button and
.0 will appear on the display. When ready to begin, press the red
pushbutton under the timer on the front panel to release the plunger for
the pre-selected amount time. The timer-controlled electromagnet will
immediately release the plunger and after the pre-selected time interval
will re-grip it to stop the test.