Abstract: 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.

Abstract: 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.

Abstract: The device includes a support tube passing through the wall of the column of the microscope, whose inner end is supported on an inner structure of the microscope by a hemispherical surface. This is supported in the wall around the orientation axis and is connected to the sample-holder which it traverses by control means enabling the position of the sample-holder to be adjusted in the support tube along three axes of a reference dihedral. The control means comprise an annular diaphragm for suspending the sample-holder in the support tube close to the center of the support surface. Lever and push-rod connecting linkages of high stiffness enable the sample-holder to be tilted around the center of the diagram in two perpendicular planes.