Pulsed wave guide liquid quality measurement

Patent metadata

Field	Value
Publication number	US-11054377-B2
Application number	US-201916364742-A
Country	US
Kind code	B2
Filing date	Mar 26, 2019
Priority date	Jun 17, 2014
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

A waveguide system may include an inner core, and a conductor wound around the inner core in conductive coils having a coil length, wherein a voltage pulse received by the pulsed waveguide propagates as an induced wave having a group velocity, the group velocity being below a threshold velocity, wherein a reflection signal or an end of line signal generated within the conductor from the induced wave is detectable from the initial voltage pulse.

First claim

What is claimed is:

1. A method of measuring quality of a liquid, comprising:
disposing at least a portion of a pulsed waveguide in the liquid, the pulsed waveguide comprising an inner core and a conductor wound around the inner core in conductive coils; receiving an initial voltage pulse in the waveguide, wherein the initial voltage pulse travels along the conductor as a wave; receiving a reflection signal or an end of line signal based upon reflection or propagation of the wave; determining a quality of the liquid from the reflection signal or end of line signal; and disposing a portion of the conductor in air, wherein the liquid comprises a urea solution having a conductivity dependent upon a concentration of urea in the liquid, and wherein the reflection signal is generated in response to a change in impedance between the air and liquid.

2. The method of claim 1 , comprising determining the quality by detecting an amplitude of the reflection signal or amplitude of the end of line signal.

3. The method of claim 1 , wherein the inner core and conductor comprise a first waveguide, wherein the liquid is a first liquid, the method further comprising:
providing a reference measurement component, the reference measurement component including a sealed container, a second waveguide disposed in the sealed container, and a second liquid having predetermined properties disposed within the sealed container, the second waveguide having identical construction as the first waveguide, the reference measurement component disposed adjacent the first waveguide;
generating a first initial voltage pulse;
detecting a first reflection signal or first end-of-line signal in the first waveguide based upon the initial voltage pulse;
detecting a second reflection signal or second end-of-line signal in the second waveguide based upon the initial voltage pulse; and
determining a quality of the first liquid by comparing the second reflection signal or second end-of-line signal to the first reflection signal or first end-of-line signal.

4. The method of claim 1 , wherein the liquid comprises a plurality of layers defining a respective plurality of boundaries, wherein the disposing comprises disposing the conductor within the plurality of layers, and wherein the receiving the reflection signal comprises receiving the reflection signal from a first boundary of the plurality of boundaries, the method further comprising:
receiving a second reflection signal from a second boundary of the plurality of boundaries; and
determining the quality of the liquid from the receiving of the second reflection signal or an amplitude of the second reflection signal.

5. The method of claim 1 , further comprising providing a ground conductor connected to ground potential and in contact with the liquid, wherein the reflection signal is generated by a low impedance path to ground from the conductor to ground conductor.

Assignees

• Littelfuse Inc

Inventors

• Johnson Brian
• Fesshaie Efrem
• Misevicius Rimantas

Classifications

• G01N27/025 Primary

  a current being generated within the material by induction · CPC title