Humboldt FD-4A, Product Manual

Page: 7 / 12

SAMPLE CALIBRATION VALUES
Tolerance = ±1% + 2 counts
POUNDS KG TOL LOW TOL HIGH
1.00 0.454 0.97 1.03
5.00 2.268 4.93 5.07
10.00 4.536 9.88 10.12
15.00 6.804 14.83 15.17
20.00 9.072 19.78 20.22
25.00 11.340 24.73 25.27
30.00 13.608 29.68 30.32
NOTES:
1. For values not shown above, use tolerance formula at top page.
2. Display should read between high and low tolerance as closely as possible to the
value of the calibration weight.
3. Analog output voltage is 1/10 of the weight. Output voltage must also be between
high and low values as calculated by tolerance limits for any given calibration
weight.
Operation
Place the FD-4A adapter on the pin of the stationary ductilometer stand in place of the
sample briquet. Use caution so as not to immerse the adapter beyond the marking.
Since the stainless steel spring plates are sensitive to temperature changes, a shift on the
digital readout maybe noticed when the adapter is immersed, especially if there is a large
difference between the water bath temperature and the ambient temperature. Allow
the adapter to stabilize for 30 to 60 minutes before conducting any testing. If necessary,
use the “zero” adjustment to set the readout (and analog output) to null. Your weight
calibrations will remain intact.
It will be necessary to determine a new starting position for the carriage of the
ductilometer. This position can be easily found by using the sample and moving the
carriage until the specimen slides freely over both the FD-4A platform pin and the
pin on the ductilometer. Note this position on the indicator and return the carriage to
this position at the beginning of each test. Now, with the sample in place, testing may
begin. Occasionally, during course of test, the force exerted on the FD-4A adapter may
exceed the 30 pound limit. Although this is not recommended, there is at least 10 pound
overload safety margin where the spring plates will not experience any deformation.
Before running the next test, be sure to check the zero setting and adjust if necessary.
If the display cannot be adjusted to zero or the analog output does not correspond
correctly with the display during calibration, it may be necessary to return the apparatus
to the factory for recalibration.
Remember:
If the unit is removed from the ductilometer and set on the calibration
stand, it must be allowed to acclimate to room temperature before any weight checks
can be made. Then readjust the zero before beginning.