Clamp-on ultrasonic flowmeter

A flow rate-measuring structure comprising a pipe in which a fluid flows and a pair of ultrasonic transmitting-receiving devices arranged on the pipe at an outer surface thereof, each transmitting-receiving device comprising a composite of an ultrasonic transducer and an ultrasonic propagating element which propagates an ultrasonic wave transmitted by the transducer predominantly in the direction perpendicular to a plane of the transducer, the composite being arranged at an acute angle from the center line of the pipe, and an ultrasonic propagating layer placed between the ultrasonic propagating element and the pipe, which has a rate of penetration of needle in the range of 10 to 300 at 25° C. and a rate of sonic propagation in terms of V1 at 25° C. satisfying the condition of 0.5<V1/V2<1.7 in which V2 represents a rate of sonic propagation of material of the pipe at 25° C., the ultrasonic propagating layer being placed in a case having an opening on a bottom surface thereof.

An ultrasonic transmitting-receiving device comprising a composite of an ultrasonic transducer and an ultrasonic propagating element which propagates an ultrasonic wave transmitted by the transducer predominantly in the direction perpendicular to a plane of the transducer, the composite being arranged at an acute angle from the center line of the pipe, and an ultrasonic propagating layer placed between the ultrasonic propagating element and the pipe, which has a viscosity in the range of 0.5×10−3 to 3×10 Pa-sec at 25° C. and a rate of sonic propagation at 25° C. is in the range of 700 to 2,000 m/sec, the ultrasonic propagating layer being placed in a case having an opening on a bottom surface thereof.

An ultrasonic transmitting-receiving device comprising a composite of an ultrasonic transducer and an ultrasonic propagating element which propagates an ultrasonic wave transmitted by the transducer predominantly in the direction perpendicular to a plane of the transducer, the composite being arranged at an acute angle from the center line of the pipe, and an ultrasonic propagating layer placed between the ultrasonic propagating element and the pipe, which has a rate of penetration of needle in the range of 10 to 300 at 25° C. and a rate of sonic propagation at 25° C. is in the range of 700 to 2,000 m/sec, the ultrasonic propagating layer being placed in a case having an opening on a bottom surface thereof.

A flow rate-measuring structure comprising a pipe in which a fluid flows and a pair of ultrasonic transmitting-receiving devices arranged on the pipe at an outer surface thereof, each transmitting-receiving device comprising a composite of an ultrasonic transducer and an ultrasonic propagating element which propagates an ultrasonic wave transmitted by the transducer predominantly in the direction perpendicular to a plane of the transducer, the composite being arranged at an acute angle from the center line of the pipe, and an ultrasonic propagating layer placed between the ultrasonic propagating element and the pipe, which has a viscosity in the range of 0.5×10−3 to 3×10 Pa-sec at 25° C. and a rate of sonic propagation in terms of V1 at 25° C. satisfying the condition of 0.5<V1/V2<1.7 in which V2 represents a rate of sonic propagation of material of the pipe at 25° C., the ultrasonic propagating element being composed of a plurality of sheet units in which each sheet unit is composed of plural high modulus fibers aligned in parallel in resinous material.

A flow rate-measuring structure comprising a pipe in which a fluid flows and a pair of ultrasonic transmitting-receiving devices arranged on the pipe at an outer surface thereof, each transmitting-receiving device comprising a composite of an ultrasonic transducer and an ultrasonic propagating element which propagates an ultrasonic wave transmitted by the transducer predominantly in the direction perpendicular to a plane of the transducer, the composite being arranged at an acute angle from the center line of the pipe, and an ultrasonic propagating layer placed between the ultrasonic propagating element and the pipe, which has a rate of penetration of needle in the range of 10 to 300 at 25° C. and a rate of sonic propagation in terms of V1 at 25° C. satisfying the condition of 0.5<V1/V2<1.7 in which V2 represents a rate of sonic propagation of material of the pipe at 25° C., the ultrasonic propagating element being composed of a plurality of sheet units in which each sheet unit is composed of plural high modulus fibers aligned in parallel in resinous material.

An ultrasonic transmitting-receiving device comprising a composite of an ultrasonic transducer and an ultrasonic propagating element which propagates an ultrasonic wave transmitted by the transducer predominantly in the direction perpendicular to a plane of the transducer, the composite being arranged at an acute angle from the center line of the pipe, and an ultrasonic propagating layer placed between the ultrasonic propagating element and the pipe, which has a viscosity in the range of 0.5×10−3 to 3×10 Pa-sec at 25° C. and a rate of sonic propagation at 25° C. is in the range of 700 to 2,000 m/sec, the ultrasonic propagating element being composed of a plurality of sheet units in which each sheet unit is composed of plural high modulus fibers aligned in parallel in resinous material.

An ultrasonic transmitting-receiving device comprising a composite of an ultrasonic transducer and an ultrasonic propagating element which propagates an ultrasonic wave transmitted by the transducer predominantly in the direction perpendicular to a plane of the transducer, the composite being arranged at an acute angle from the center line of the pipe, and an ultrasonic propagating layer placed between the ultrasonic propagating element and the pipe which has a rate of penetration of needle in the range of 10 to 300 at 25° C. and a rate of sonic propagation at 25° C. is in the range of 700 to 2,000 m/sec, the ultrasonic propagating element being composed of a plurality of sheet unites in which each sheet unit is composed of plural high modulus fibers aligned in parallel resinous material.