Li-cor, Inc.

Robert D Eckles

Dayle K McDermitt

Mark A Johnson

Jonathan M Welles

Lyle R Middendorf

Robert Clark Bruce

Michael D Furtaw

Tyler Anderson

Georgiy G Burba

Daniel J Anderson

Jason Hupp

Douglas J Lynch

Johnathan I E McCoy

Bernard Genty

Andrew S Parr

Dayle K Mcdermitt

Tyler G Anderson

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

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 multi-pass optical cell with an actuator for actuating a reflective surface is provided. In one preferred embodiment, an apparatus is provided comprising a first reflective surface, a second reflective surface, and a support structure supporting the first and second reflective surfaces. The support structure positions the first and second reflective surfaces to create an optical cell. The apparatus also comprises a source and a detector, which are positioned such that light emitted from the source is reflected in the optical cell at least one time between the first and second reflective surfaces before reaching the detector. The apparatus further comprises an actuator coupled with and operative to actuate the first reflective surface. In some embodiments, the actuator rotates the first reflective surface. Also, in some embodiments, the multi-pass optical cell is an open path multi-pass optical cell, while, in other embodiments, the multi-pass optical cell is a closed path multi-pass optical cell.

Multi-pass optical cell with actuator for actuating a reflective surface

Gas analyzer systems and methods for measuring concentrations of gasses and in particular dry mole fraction of components of a gas. The systems and method 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 in field cleaning of optical components.

Gas analyzer

Gas analyzer systems and methods for determining gas flux in a short intake tube configuration without using any Webb-Pearman-Leuning density correction. Gas analyzer systems and methods for measuring concentrations of gasses and in particular dry mole fraction of components of a gas. The systems and method 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 in field cleaning of optical components.

In one preferred embodiment, a gas analyzer is presented that focuses light beams through gas cells without reflecting the light beams off the walls of the cells. By eliminating wall reflections, dirt or debris on the walls of the cells will not result in inaccurate gas concentration measurements. In another preferred embodiment, a gas analyzer is disclosed having removable gas cells, which allows a user to easily clean the cells instead of returning a contaminated gas analyzer to service personnel for cleaning. In yet another preferred embodiment, a gas analyzer has a purged gas flow channel between source and detector sections of the analyzer to remove contaminants that can result in inaccurate gas concentration measurements. In an additional preferred embodiment, a gas analyzer is disclosed which has a heat exchanger to equilibrate the temperature of incoming air to the temperature of the analyzer's gas cells, thereby avoiding temperature-based errors in gas concentration measurements.

The present gas analyzer allows for the effective measurement of the concentration of one or more gases or vapors within a sample. The gas analyzer utilizes a plurality of reference filters that are located between the source and the sample region to enhance the measurements associated with the sample filters. The gas analyzer also utilizes a gas channel to facilitate the circulation of scrubbed gas between two separate housing sections.

To sequence DNA, DNA samples marked with flourscent infrared dye are applied at a plurality of locations for electrophoresing in a plurality of channels through a gel electrophoresis slab. The channels are scanned with a laser and a sensor, that include a microscope focused on the gel slab. The focal point and slab are adjusted with respect to each other so that the focal point of the microscope remains on the gel slab during a scan. The data from the scan is directly used to amplitude modulate density readings on a display, and the scan is displayed in a horizontal sweep of a cathode ray tube, whereby said cathode ray tube provides intensity displays of bands representing DNA. Different sizes of glass gel sandwiches may be mounted to the same console for different sequencing tasks.

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Malcolm, NE, United States of America

Robert D Eckles