Humboldt FD-4A, Product Manual

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Installation
Connections and Start-up:
Carefully unpack the FD-4A apparatus. Save the box and packing materials in the event
that the unit must be shipped in the future. The FD-4A adapter maybe placed on the
calibration stand for hook at this time. Be sure to secure the test stand before hanging
weights-refer to instructions under “calibration”. Connect the power cord to the
DTR-451 Digital Transducer Readout and to a 120 VAC grounded outlet. Connect the
DTR-451 to the FD-4A using the attached cable with the 9-pin plug. Both sockets are
located on the rear of the Digital Readout unit. Turn the unit on and allow it to warm up
for 30 minutes or more. To reduce display variations due to temperature fluctuations it is
recommended that the unit be left “on” 24 hours/day. Be sure the “HI-LO Sens” switch
is in the “LO” position. This is a 10 to 1 ratio option for the display which will not be
used in most test situations. (If the numbers flash on “HI Sens”, it means the readings is
too large to be displayed). Unless you are using metric, check to see that the “English/
Metric” switch is set on “English”. The DTR-451 unit will display pounds to two decimal
places. On the metric scale it will display kilograms to the same resolution.
Output Connections:
At this time, you may also wish to connect your strip chart recorder or data acquisition
device. An analog output voltage is available on the 15-pin connector on the rear of the
DTR-451 unit. A matching plug is furnished. The connections are soldered as follows:
1 is output (red), 2 is common (black), and 3 is the shield (not used). A meter, recorder,
analog-to-digital converter, computer or other readout device may be used. One tenth
of one volt output is equal to one pound of force on the adapter. Additional information
regarding the 15-pin connector and the optional BCD interface (if required) is available.
Calibration
Set-up:
The FD-4A apparatus is factory calibrated before shipment and is ready to use. It is
recommended, however, that the “zero” adjustment be checked regularly as well as
other settings described below. Warning: before attempting any calibration, secure
the test stand to a bench or work table by either clamping it down on the back end or
using screws in the holes provided. This will prevent the weights from tipping the device
forward. Locate the stand with minimum extension beyond the edge of the mounting
surface as required to clear the weights. Be certain the stand is installed level preferably
by adjusting the bench or table. Use shims under the calibration stand if this is not
possible. Caution: do not over tighten the screws or clamp as this may cause the stand
to warp. It is also necessary to have a container filled with cushioning materials at all
times directly below where the weights hang. If the weights fell for some reason, this
precaution would reduce the potential for damage and injury to personnel. After the
calibration stand is level and secured to the work surface, the FD-4A adapter can be
placed in position on the retaining pin. The DTR-451 readout units must be warmed up
and the FD-4A adapter stabilized at room temperature before calibrations can be made.
The weight holder cable can now be located in the pulley groove so the platform block
fits on the FD-4A adapter pin. Slotted weights placed on the weight holder base will
apply force to the adapter platform so the digital readout unit can be checked.