# US 7,610,816 B2 · Flow measurement device

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- Number: US 7,610,816 B2
- Document ID: US7610816B2
- Status: Granted
- Kind: B2
- Application number: 12/148,587
- Filed: 2008-04-21
- Published: 2009-04-30
- Granted: 2009-11-03
- Earliest claimed: 2008-04-21
- Assignees: Ohm Electric Co., Ltd.
- Inventors: Tadao Okazaki
- Web page: https://patentgrep.com/patent/US7610816B2

## CPC

- G01F 1/74: Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid
- G01F 1/56: by using electric or magnetic effects (G01F1/66 takes precedence)
- G01F 1/66: by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
- G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME

## Abstract

The present invention discloses a flow measurement device that includes: a wave guide tube type resonant cavity; a penetrating space that penetrates the resonant cavity; a duct support part that is made of a dielectric substance and is in the resonant cavity and surrounds an outside of the penetrating space; a transmitting antenna that transmits a microwave in a direction along a longitudinal axial direction of the resonant cavity to provide a standing wave or a traveling wave of the microwave, with the microwave transmitted in a space that is outside of duct support part and inside of the resonant cavity; and a receiving antenna that receives the standing wave or the traveling wave.

## Claims

### Claim 1

A flow measurement device, comprising:
a wave guide tube type resonant cavity;
a penetrating space that penetrates the resonant cavity;
a duct support part that is made of a dielectric substance, is in the resonant cavity and surrounds an outside of the penetrating space;
a transmitting antenna that transmits a microwave transmitting to a direction along a longitudinal axial direction of the resonant cavity to provide a standing wave or a traveling wave of the microwave, the microwave is transmitted in a space that is outside of duct support part and inside of the resonant cavity; and
a receiving antenna that receives the standing wave or the traveling wave.

### Claim 2 (depends on 1)

A flow measurement device as set forth in claim 1, further comprising:
a metal cylinder that protrudes to outside from an opening of the penetrating space of the resonant cavity and has an opening diameter smaller than an inner diameter of the resonant cavity.

### Claim 3 (depends on 1)

A flow measurement device as set forth in claim 1, wherein:
the resonant cavity is formed in separable so that entire of the penetrating space can be exposed.

### Claim 4 (depends on 1)

A flow measurement device as set forth in claim 1, wherein:
the standing wave is provided in the resonant cavity; and
the flow measurement device calculates a flow velocity of a dielectric fluid flowing in the penetrating space based on a frequency of an alternate current component of a received electric power received by the receiving antenna.

### Claim 5 (depends on 1)

A flow measurement device as set forth in claim 1, wherein:
the standing wave is provided in the resonant cavity; and
the flow measurement device calculates a volume of a dielectric fluid flowing in the penetrating space based on a amplitude of an alternate current component of a received electric power received by the receiving antenna.

### Claim 6 (depends on 5)

A flow measurement device as set forth in claim 5, wherein:
the flow measurement device modifies the volume based on a direct current component of the received electric power received by the receiving antenna when the volume is calculated.

### Claim 7 (depends on 1)

A flow measurement device as set forth in claim 1, wherein:
the traveling wave is provided in the resonant cavity; and
the flow measurement device calculates a flow velocity of a dielectric fluid flowing in the penetrating space based on a Doppler frequency of the microwave received by the receiving antenna.