Instrumented drop weight apparatus

The assemblies of the transparent anvil drop weight apparatus and the instrumented drop weight apparatus are shown in Figures 3.12 and 3.13... 

Figure 3.13 Instrumented drop weight apparatus. Reprinted with permission from Field, J.E., Swallowe, G.M., Palmer, S.).P., Pope, P.H., and Sundarajan, R. (1985) Proc. 8th Symp. (Inti) on Detonation 1985, Naval Surface Warfare Center, USA...

Vapour pressure osmometry VPO). At present commercially available apparatus for VPO is the Corona molecular-weight apparatus models 114 and 117 manufactured by the Corona Co., which have been produced in the past by Hitachi Co. Ltd Knauer Vapour Pressure Osmometer No. 731.110000 (Dr. H. Knauer Wissenschaftliche Cerate, AG) Jupiter Model 233 Vapour Pressure Osmometer (Jupiter Instrument Co. Inc.) and Gonotec model 070 (Gonotec Gesellschaft fiir MeB- und Regeltechnik m6H). A typical VPO apparatus consists of (1) two thermistors covered with glass, to which solution and solvent drops are attached (2) a cell, the interior of which is saturated with solvent vapour (3) a solvent vessel, placed at the lower part of the cell and (4) an electronic circuit. The instrument is usually thermostatted. 

Vapor Pressure Osmometry. VPO is a very practical method for determining Mn values in a wide range of solvents and temperatures. Recently, results obtained with classical pendant-drop instruments showed a significant dependence of the calibration constant upon the molecular weight of the standards (8,9). On the other hand, with an apparatus equipped with thermistors allowing the volume of the drops to be kept constant, this anomaly is not observed (10,11). 

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