Apparatus and method for detecting liquid level in a clear or partially clear container
Inventors
Assignees
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Publication Number
US-11554235-B2
Publication Date
2023-01-17
Expiration Date
Abstract
A trap bowl is provided to accumulate liquid droplets from a filter, as a liquid content. The trap bowl includes a transparent vertical prism. The transparent vertical prism includes a face that forms a vertical transparent surface facing against a content of the section. The face can provide a first angle of total reflection when content of the section is a type of gas, and a second angle of total reflection when the content of the section is the liquid content. A light source may emit a light beam incident on the face at an angle of incidence. The angle of incidence results in reflection of the light beam, striking the light receiver, when the face has the first angle of total reflection, and results in refraction of the light beam, missing the light receiver, when the face has the second angle of total reflection.
Core Innovation
The invention relates to a filter trap apparatus for sampled inspiratory breathing gas that accumulates liquid droplets as a liquid content in a trap bowl. The trap bowl includes a section extending in a vertical direction and a transparent vertical prism, and the transparent vertical prism includes a face forming a vertical transparent surface facing against the content of the section.
The face has a first angle of total reflection when the content is a gas and a second angle of total reflection when the content is the liquid content. A light source emits a light beam incident on the face at an angle of incidence such that, with the first angle of total reflection, the light beam is reflected and strikes a first optical receiver, and with the second angle of total reflection, the light beam is refracted and misses the first optical receiver.
The apparatus further includes a second optical receiver that is an offset optical receiver from the first optical receiver and a third optical receiver that is a diametrically opposed optical receiver from the first optical receiver. The first, second, and third optical receivers are arranged on a same plane that is normal to a vertically extending center axis of the trap bowl.
Claims Coverage
The independent claim covers a filter trap apparatus with a vertically extending trap bowl, a transparent vertical prism having gas/liquid-dependent total-reflection angles, and optical receivers arranged on a common plane normal to the trap bowl axis. The main inventive features include prism-based switching of reflected versus refracted light and a receiver arrangement providing multiple detection positions.
Transparent vertical prism with gas/liquid-dependent total reflection
A transparent vertical prism including a face that forms a vertical transparent surface facing against a content of the section, the face having a first angle of total reflection when the content of the section is a gas, and a second angle of total reflection when the content of the section is the liquid content.
Light beam incidence that reflects to a first optical receiver for gas and refracts away for liquid
A light source configured to emit a light beam incident on the face at an angle of incidence, wherein the angle of incidence results in reflection of the light beam, striking the first optical receiver, when the face has the first angle of total reflection, and results in refraction of the light beam, missing the first optical receiver, when the face has the second angle of total reflection.
Offset and diametrically opposed optical receivers on a normal plane
A second optical receiver that is an offset optical receiver from the first optical receiver and a third optical receiver that is a diametrically opposed optical receiver from the first optical receiver, wherein the first optical receiver, the second optical receiver, and the third optical receiver are on a same plane that is normal to a vertically extending center axis of the trap bowl.
Across the independent claim, the core coverage is defined by a transparent vertical prism with different total-reflection angles for gas versus liquid content, a light source and incidence angle that produce reflection to the first optical receiver for gas and refraction away from it for liquid, and an optical receiver arrangement with an offset receiver and a diametrically opposed receiver on a common plane normal to the trap bowl’s vertical center axis.
Stated Advantages
Enables optical determination of whether the content of the section is a gas or the liquid content by using total internal reflection behavior that changes with liquid covering the prism interface.
Documented Applications
Used in an inhaled nitric oxide (iNO) sampling system with a ventilator breathing circuit and a sample gas line for monitoring fill state and installation verification.
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