ULTRASONIC FLOW SPEED*RATE METER CAPABLE OF AUTOMATIC SWITCHING BETWEEN TRANSMISSIONNTYPE AND REFLECTIONNTYPE MEASURING MODES

摘要

PURPOSE:To ensure a continuous measurement of the flow speed/rate for the fluid to be measured and having the varying state of turbidity, by securing an automatic switching between the ultrasonic transmission-type measuring mode and the Doppler reflection-type measuring mode in accordance with the state of turbidity of the fluid to be measured. CONSTITUTION:The means 6 and 8 plus 10 and 11 which detect the state of turbidity of the fluid 1 to be measured are provided, along with the switching control part E which gives an automatic selection between the processing part of the transmission-type measuring mode signal C utilizing the propagation time of the ultrasonic wave and the processing part of the reflection-type signal D utilizing the Doppler shift. Thus the reflection-type measuring mode and the transmission-type measuring mode are used when the concentration of turbidity is high and low rspectively in accordance with the state of turbidity of the fluid 1. As a result, a continuous measurement is possible for the flow speed/rate of the fluid 1 which has the varying state of turbidity.