GAS EXCHANGE SYSTEM FLOW CONFIGURATION

摘要

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.

主权项

1. A gas exchange analysis sensor head apparatus comprising:
an active flow splitting device having a first output port and a second output port, the active flow splitting device configured to variably split an incoming gas flow between the first and second output ports; a sample chamber having an inlet and an outlet, the inlet coupled with the first output port of the active flow splitting device; a first gas analyzer coupled with the outlet of the sample chamber and configured to measure a concentration of a gas; a second gas analyzer coupled with the second output port of the active flow splitting device and configured to measure a concentration of said gas; a flow meter coupled between the first output port of the active flow splitting device and the inlet of the sample chamber or between the second output port of the active flow splitting device and the second gas analyzer, the flow meter configured to measure a flow rate; and a feedback control circuit adapted to control the active flow splitting device to adjust the incoming gas flow to the first and second output ports responsive to a flow rate signal from the flow meter.