Miller 



The zero terms in the above equations represent interactions that were not 

 measurable or were too small to be significant. Only the (T, e^), (Mj, ef^), 

 and the (Mj, ef^) terms are due to inaccuracies in the balance. The (Fj , e^ ) 

 and (F2 , e^^) terms are inherent to the design and due to the fact that the cen- 

 ter of the propeller is displaced axially from the moment center of the balance. 

 The remaining terms, on the diagonal, are of course the principal responses of 

 the balance to the six components. 



Fig. 7 - Six-component balance 



0.5 



0.4 



O In Air 

 X In Water 



THRUST 



60 80 100 200 



Frequency 



Fig. 8 - Dynamic calibration of thrust 



400 600 800 



262 



