Ultrasonic meter with single transducer
A metering system uses an electronics assembly with a single transducer to determine flow rate. The meter assembly emits an ultrasonic beam from the transducer and splits the ultrasonic beam into a first partial beam and a second partial beam. The first partial beam is transmitted over a first path that returns to the electronics assembly, and the second partial beam is transmitted over a second path that returns to the electronics assembly. The first path goes over a first net distance of a measuring channel. The second path goes over a second net distance of the measuring channel. The meter assembly detects the return of the first partial beam and the second partial beam, measures a time difference between the return times, and determines a measurement of a fluid flow through the measuring channel based on the time difference.
1 . A method performed by a meter assembly, the method comprising:
emitting an ultrasonic beam from a single transducer;
splitting the ultrasonic beam into a first partial beam and a second partial beam, wherein the first partial beam is transmitted over a first path that returns to the transducer, and wherein the second partial beam is transmitted over a second path that returns to the transducer;
directing the first partial beam, via the first path, through a stationary medium and over a first net distance of a measuring channel;
directing the second partial beam, via the second path, over a second net distance of the measuring channel and through the stationary medium;
detecting at the transducer a return of the first partial beam and a return of the second partial beam;
measuring a time difference, based on the detecting of the first partial beam and the second partial beam, between a first time of flight of the first partial beam and a second time of flight of the second partial beam; and
determining a measurement of a fluid flow through the measuring channel based on the time difference.
2 . The method of claim 1 , wherein emitting the ultrasonic beam includes emitting one of a pulse or a wave packet.
3 . The method of claim 1 , wherein splitting the ultrasonic beam includes one or more of:
directing the ultrasonic beam to a reflector that does not entirely obstruct the ultrasonic beam,
directing the ultrasonic beam onto a reflector that has at least two different reflective surfaces, or
directing the ultrasonic beam onto a partial reflector that partially reflects the ultrasonic beam and allows a portion of the ultrasonic beam to pass through.
4 . The method of claim 1 , wherein the stationary medium includes a solid material.
5 . The method of claim 1 , wherein the stationary medium includes a fluid.
6 . The method of claim 1 , wherein directing the first partial beam through the measuring channel includes exposing the first partial beam to the fluid flow through the measuring channel in a net streamwise distance in the direction of the fluid flow; and
wherein directing the second partial beam through the measuring channel includes exposing the first partial beam to the fluid flow through the measuring channel in a net streamwise distance in a direction opposite the fluid flow.
7 . The method of claim 1 , wherein the first time of flight is different from the second time of flight when a rate of fluid flow through the measuring channel is zero.
8 . The method of claim 1 , wherein the stationary medium and a fluid of the fluid flow are the same fluid.
9 . A fluid meter assembly, comprising:
a measuring channel;
a stationary medium;
an electronics assembly including a transducer configured to emit an ultrasonic beam;
a beam splitter configured to split the ultrasonic beam into a first partial beam and a second partial beam;
a first set of reflectors configured to direct the first partial beam over a first path that returns to the electronics assembly, wherein the first path includes the stationary medium and a first net distance of a measuring channel; and
a second set of reflectors configured to direct the second partial beam over a second path that returns to the electronics assembly, wherein the second path, includes a second net distance of the measuring channel and the stationary medium;
wherein the electronics assembly is configured to:
detect a return of the first partial beam and a return of the second partial beam,
measure a time difference, between a first time of flight of the first partial beam and a second time of flight of the second partial beam, and
determine a measurement of a fluid flow through the measuring channel based on the time difference.
10 . The fluid meter assembly of claim 9 , wherein transducer is configured to transmit the ultrasonic beam as one of a pulse or a wave packet.
11 . The fluid meter assembly of claim 9 , wherein the beam splitter comprises:
a reflector that does not entirely obstruct the ultrasonic beam,
a reflector that has at least two different reflective surfaces, or
a partial reflector that partially reflects the ultrasonic beam and allows a portion of the ultrasonic beam to pass through.
12 . The fluid meter assembly of claim 9 , wherein the stationary medium includes a solid material.
13 . The fluid meter assembly of claim 9 , wherein the stationary medium includes a fluid.
14 . The fluid meter assembly of claim 9 , wherein the first time of flight is different from the second time of flight when a rate of fluid flow through the measuring channel is zero.
15 . The fluid meter assembly of claim 9 , wherein a length of the first path is different than a length of the second path.
16 . The fluid meter assembly of claim 9 , wherein the stationary medium and a fluid of the fluid flow are the same.
17 . An electronics module for a fluid meter, the electronics module comprising:
a transducer configured to:
emit an ultrasonic beam into a measuring channel, and
detect return of a first partial beam and return of a second partial beam of the ultrasonic beam; and
a processor configured to:
measure a time difference, based on the detecting, between a first time of flight of the first partial beam and a second time of flight of the second partial beam, and
determine a measurement of a fluid flow through the measuring channel based on the time difference.
18 . The electronics module of claim 17 , wherein the measurement of the fluid flow is an absolute value.
19 . The electronics module of claim 17 , wherein the measurement of the fluid flow includes a directional value.
20 . The electronics module of claim 17 , wherein the processor is further configured to:
associate the first partial beam with a first beam path having a first path length, and
associate the second partial beam with a second beam path having a second path length.