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BELL SYSTEM TECHNICAL JOURNAL 



rately determined. Fig. 6.12 is a more detailed representation of the 

 conditions shown broadly in Fig. 6.11 except in this case an .4C-cut quartz 

 plate was used and most of the observable resonant frequencies are shown 



Fig. 6.12 — Shear and flexure resonances in an ,4C-cut quartz plate. 

 W I 



for various values of — . The plate shear is labeled Z^ shear and occurs at 



the frequencies predicted by equation 6.8 except in the regions where a 

 flexure in the same plane exists. This is the type of motion shown in Fig. 

 6.4 for the case of m = I, n = 1. It can be seen that as the difference 

 in order of modes becomes greater the effect on the shear frequency is less 



