Humboldt H-1068 Series Ductility Testing Machines - Manual (Page 5)

Place the specimen in position by setting one end of the specimen mold into
one of the three mounting pins on the end plate. Set the other end of the mold
into the corresponding pin on the movable carriage.
Move the length indicator to the zero position on the scale located on the upper
side of the tank by loosening the adjusting screw. The length indicator will then
read the distance the specimen has been pulled apart in centimeters.
At the completion of the test return the carriage to the starting position.
Note: If the test material comes in contact with the surface of the water or the
bottom of the bath, the test is not considered satisfactory. The specific gravity
of the bath may be adjusted by the addition of either methyl alcohol or sodium
chloride to prevent the bituminous sample from coming to the surface of the
water or touching the bottom of the bath during the test.
Operating Instructions
The Temperature Controlled Ductility Machine has a separate thermostatically
controlled constant temperature circulator with recommended fluids circulating
through finned tubes in the trough. Recommended circulator fluids are 50/50
filtered or distilled water and glycol to maintain a constant temperature of within
± 0.9°F (0.5°C).
Test Report
The test is considered normal when the rupture occurs at the point where the
thread has practically no cross-sectional area.
The average of three normal tests is reported as the ductility of the sample.
Maintenance
All bearing surfaces should be kept clean. the oil cups provide for adding SAE
Grade 30 lubricating oil. Threaded lead screw should be kept clean and properly
greased to ensure proper carriage level travel. Use NGLI #2 Extreme Pressure
Lithium Grease or equivalent on the threads. When not in use, remove line cord
from the outlet to prevent misuse or improper handling.