DYNAMIC MEASUREMENTS ON ELECTROMAGNETIC DT.VTr T.s 1 1")7 



If longer cycle times were needed without the short times ol pi. ( ni 

 interest, the inductance could be appropriately increased, and iUv ampli- 

 fier bandwidths correspondingly decreased, without loss of accuracy. 



Summary of Amplifier Discussion 



The foregoing discussion of the amplifiers covers the design considera- 

 tions, the required frequency responses, and errors because of divergence 

 from the ideal. For displacement measurements, all events occur in 

 intervals greater than the minimum which the amplifiers can follow. 

 This is also true of velocity measurements as regards the photocell 

 amplifier and differentiator. The output amplifier does overload mo- 

 mentarily at jump discontinuities of velocity, and in the time vicinity 

 following such events is in error. 



Another type of error caused by variations in successive operations of 

 the device being tested can be corrected by use of the measured rates 

 just before and after the discontinuity. 



