Vibrating beam apparatus, resonant

Fig. 7.21. Schematic diagram of the droplet beam apparatus used by the group of the late Roger Miller at the University of North Carolina to study isomerization of HCN HF van der Waals complexes. The HCN and HF molecules are first picked up separately to form oriented van der Waals complexes inside the droplets. The CH or HF stretch vibrations are used to excite the complex and after a flight time of 175 ns to probe the isomers formed. The corresponding laser resonances are monitored by the increase or depletion of the droplet signal at the downstream bolometer detector. Adapted from Ref. 57.

Various methods (1-1) have used to determine the dynamic mechanical properties of polymers. Many of the instruments described are well known and are widely used (torsional pendulum, rheovibron, vibrating reed, and Oberst beam ASTM D4065-82). Newer instruments like the torqued cylinder apparatus (4), resonant bar apparatus (5) and Polymer Laboratories Dynamic Mechanical Thermal Analyzer (6) are becoming more popular in recent times. 

---