SIREN VALVE 

 PHASE-LOCK 

 DRIVE 



'SI LENT' THROTTLE 

 VALVE 



HYDRAULIC CONTROL 



DOWNSTREAM LASER 

 & PRESSURE 

 MEASUREMENT 

 STATION 



DOWNSTREAM FLOW 

 SMOOTHING SECTION 



VOLUTE- 

 TRANSPARENT HOUSING 

 & IMPELLER (7.59 CM DIA) 'WINDOW 



PHOTOMULTIPLIER & UPSTREAM - UPSTREA m FLOW 

 MEASURING STATION SMOOTHING SECTION 



PLAN VIEW 



UPSTREAM SIREN 

 VALVE 



30% OPEN AREA 

 BAFFLE (2 PL) 



Figure 40 - Test Loop for Dynamic Transfer Function Measurement 



(Ng 1976) 



