Li-cor, Inc.

Other

Mark A Johnson

Robert D Eckles

Dayle K McDermitt

Andrew George Ragatz

Jason Hupp

Douglas J Lynch

Rex A Peterson

Michael D Furtaw

Tyler Anderson

Johnathan I E McCoy

Andrew S Parr

Bernard Genty

Bob Eckles

Systems and method for minimizing the impact of water vapor or other interferent analyte on analyte concentration measurements in a gas exchange measurement system. A system is includes a gas source, first and second gas analyzers coupled to first and second gas flow lines and configured to measure first and second concentrations of a target analyte in the first and second gas flow lines, respectively, a sample chamber configured to hold a water saturable sample, and a water vapor selective element and having a first and second inputs fluidly coupling the gas source to first and second sides, respectively, of the water vapor selective element, and at least one output fluidly coupling the first side of the water vapor selective element to the first and second gas flow lines and a second output coupling the second side of the water vapor selective element to the second gas flow line.

Water vapor differential minimization systems and methods for gas exchange measurements of aqueous or water saturated samples

Gas exchange analysis methods and systems utilize a water vapor buffering component including a material configured to buffer water vapor in a flow of a gas, whereby fluctuations in the water vapor content in the flow of the gas are slowed for components downstream from the water vapor buffering component. Components downstream of the water vapor buffering component may include: a first water vapor sensor configured to receive the flow of the gas from the water vapor buffering component and configured to measure a first concentration of water vapor in the gas; a sample chamber configured to receive the gas exiting the water vapor buffering component or the first water vapor sensor and to hold a sample capable of adding or removing water vapor from the gas; and a second water vapor sensor configured to measure a second concentration of water vapor in the gas exiting the sample chamber.

Gas exchange transient buffering systems and methods

Multi-functional piezo-actuated flow control systems and methods for use in gas exchange analysis systems such as photosynthesis measurement systems. A fluid valve assembly module includes a housing structure including a plurality of ports and a plurality of fluid passageways interconnecting the ports, and a plurality of piezo-actuated valves in fluid communication with the fluid passageways, each valve including a piezo element that controls flow along a passageway, wherein the passageways and valves are arranged within the housing structure so as to define a fluid control module, which includes a flow swapping component, a flow splitting component and a flow pressurization component. The flow swapping component has first and second inlets and first and second output ports and is configured to receive a first fluid flow at the first inlet and a second fluid flow at the second inlet and in a first operational mode to direct the first fluid flow to the first output port and the second fluid flow to the second output port, and in a second operational mode to direct the first fluid flow to the second output port and the second fluid flow to the first output port. The flow splitting component has an input port, a third output port and a first outlet and is configured to receive an input fluid flow at the input port and to control an amount of the input fluid flow provided to the third output port and to the first outlet in a continuously adjustable manner, wherein the first outlet is fluidly connected to the first inlet of the flow swapping component and the third output port is adapted to be fluidly coupled with an external reservoir. The flow pressurization component has an entry port in fluid communication with a second outlet and is configured to receive a third fluid flow at the entry port and to control the pressure of the third fluid flow at the second outlet, wherein the second outlet is fluidly connected to the second inlet of the flow swapping component and the entry port is adapted to be fluidly coupled with the external reservoir.

Multi-functional piezo actuated flow controller

Active compensation designs to offset the impact of gas diffusion sources and sinks in a photosynthesis and transpiration measurement system are disclosed. A sensor head for use in a gas exchange analysis system includes an active, piezoelectric flow splitting device for splitting a flow between a sample chamber and bypass pathway. The active flow splitting device is controlled by feedback from a downstream flow meter. A continuous measurement system for rapidly and accurately surveying large numbers of samples is described.

Gas exchange system flow configuration

Gas analyzer systems and methods for measuring concentrations of gases and in particular dry mole fraction of components of a gas. The systems and methods allow for rapid measurement of the gas density and/or dry mole fraction of gases for a number of environmental monitoring applications, including high speed flux measurements. A novel coupling design allows for tool-free removal of a cell enclosing a flow path to enable infield cleaning of optical components and to enable re-configuration between open- and closed-path analyzer configurations. In closed path configurations, the sample flow path is thermally isolated from the remainder of the gas analyzer to provide more accurate temperature measurements. Composite plastic/metal sample cells are presented with achieve this thermal isolation without compromising analyzer performance.

Hybrid gas analyzer with thermally insulated flow cell

System flow path designs that minimize the impact of gas diffusion sources and sinks. By reducing the magnitude of parasitic sources and sinks, lower rates of photosynthesis and transpiration can be more accurately measured, e.g., without the need for extensive empirical compensation. The gas exchange analysis system includes a sample chamber having an inlet and an outlet, wherein the internal surface(s) of the chamber defining the measurement volume are metal plated. The system also typically includes a source of gas coupled with the inlet of the sample chamber, and a gas analyzer coupled with the outlet of the sample chamber and configured to measure a concentration of one or more gases exiting the chamber, whereby the metal plated internal surface(s) of the chamber reduces sorption of the one or more gases within the chamber.

Gas exchange system flow configuration with thermally insulated sample chamber

System flow path designs that minimize the impact of gas diffusion sources and sinks. By reducing the magnitude of parasitic sources and sinks, lower rates of photosynthesis and transpiration can be more accurately measured, e.g., without the need for extensive empirical compensation. According to one aspect, a sensor head for use in a gas exchange analysis system includes a sample chamber defining a measurement volume for analysis of a sample, the sample chamber having an inlet and an outlet, and a flow splitting mechanism located proximal to the sample chamber, the mechanism configured to split a gas flow received at an input port from a remote source to a first output port and to a second output port, wherein the first output port is coupled with the inlet of the sample chamber. The sensor head also typically includes a first gas analyzer coupled with the outlet of the sample chamber and configured to measure a concentration of one or more gases, and a second gas analyzer coupled with the second output port of the flow splitting mechanism and configured to measure a concentration of the one or more gases. Advantageously, gas diffusion sources and sinks are reduced due to the proximity of the flow splitting mechanism with the sample chamber and gas analyzers. This advantageously reduces measurement error associated with or attributable to gas diffusion sources and sinks. The proximity advantage derives from minimizing the joints, gaskets, fittings, tubing lengths, and materials all prone or susceptible to gas diffusion.

A safety system for a door-to-door jamb interface is provided. The safety interface uses several slidably joined members which are coupled to the door and its associated door jamb to prevent interaction between a user and the door-to-door jamb interface.

Door safety device

A gas flux chamber assembly is provided that includes a lift-and-rotate mechanism and a chamber. The chamber is moved between first and second positions, wherein the chamber is positioned over a sample in the first position and is positioned outside of an area above the sample in the second position. In operation, the chamber is first lifted off of the collar and is then rotated, about a rotational axis outside of the area above the collar. These acts are reversed to move the chamber from the second position to the first position.

Gas flux system chamber design and positioning method

A gas flux chamber assembly with a soil collar and a chamber is provided. The chamber is moved between first and second positions, wherein the chamber is positioned on the soil collar in the first position and is positioned outside of an area above the soil collar in the second position. In operation, the chamber is first lifted off of the soil collar and is then rotated, about a rotational axis substantially parallel to the soil collar axis, outside of the area above the soil collar. These acts are reversed to move the chamber from the second position to the first position.

A musical instrument capable of producing the sound spectrum associated with a traditional Australian didjeridoo, but in a more compact and portable form. In certain embodiments, an air column follows a tortuous path between a mouthpiece, having an input orifice between about one to about one-and-one-half inches in diameter, and an exit port. The air column is housed within a body having a length. The ratio of length of the air column to the instrument body length is preferably greater than 1.5 to provide a compact instrument. The instrument may be manufactured tuned to a traditional key-scale note, and may include tone holes to play other fundamental notes. In certain embodiments, a vibrating membrane may be provided in sealed relation over one or more through-holes in the body to produce other sounds of which a traditional didjeridoo is incapable.

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Lincoln, NE, United States of America

Mark A Johnson