Humboldt H-1820 Large-Capacity Vacuum Pycnometer - Manual (Page 4)

Calculations (From ASTM D2041-00, Section 10)
If the test temperature is within 72°F and 80°F, Equation 1, maybe used to calculate
specific gravity within 0.001 points or less error due to the thermal effects.
Equation 1
Where:
A = Mass of dry sample in air, G
D = Mass of container filled with water at 77°F, G
E = Mass of container filled with water and sample at 77°F
If the test temperature differs significantly from 77°F, correct for thermal effects as
follows:
Equation 2
Where:
A = Mass of dry sample in air, G
F = Mass of Pycnometer filled with water at test temperature, G
G = Mass of Pycnometer filled with water and sample at test temperature, G
H = Correction for thermal expansion of bitumen, G
DW = Density of water at test temperature, MG/M3
0.9970 = Density of water at 77°F. MG/M3
For details see ASTM D2041-00, Section 10
Troubleshooting
• Pycnometer not getting vacuum:
1. Check “o-ring” to make sure it is clean and in good shape. If not, get a
replacement “o-ring” from your distributor.
2. Check to make sure the water inlet valve is on tight.
3. Tighten the stopcock nut (at the bottom of stopcock) of the water inlet valve.
• Air bubbles entering from the Water Inlet Valve:
1. Follow the procedure of 2 and 3 above.
• Clogged in-line filter
1. Replace the filter assembly.
• Too many air bubbles in water.
Air bubbles come from dissolved in water. You can check for this by opening water inlet
valve (keeping the water inlet hose connected to the water supply) after you have gone
through step 8 of the operating procedure. The air bubbles should dissolved back in
water at atmospheric pressure.
Try filling the pycnometer with boiled water (after it has been cooled).
IF PROBLEM STILL PERSISTS, CONTACT HUMBOLDT MFG. COMPANY FOR
ASSISTANCE.