Wo imicapesy 20 kc 
Transmitter Modulation 
1.6 m.c. p.s. 
Transmitter 
Receiver Receiver 
Phase Phase 
Shifter Meter 
Output 
Block Diagram of 0-15 ft./sec. Acoustic Flow Meter Using 
Four Transducers 
Fig. 1 
Pulsed 20 kc 
Transmitter Modulation 
ia 112 
Output 
Block Diagram of 0-15 ft./sec. Acoustic Flow Meter 
Fig. 2 
202 
