A method and apparatus are disclosed for assessing gas exchange of plants. The method includes receiving in a gas analyzer a plurality of test air samples from a leaf chamber corresponding respectively to first and second plant leaf samples received separately and in sequence in the leaf chamber while being exposed to light to form the first and second test air samples, the first and second test air samples being received in sequence in the gas analyzer as an integrated gas stream, and the gas analyzer analyzing the integrated gas stream as it flows therethrough. The measuring apparatus includes a leaf chamber for receiving therein a plant leaf sample to be tested, a pump communicating with the leaf chamber for supplying air thereto, and an analyzer communicating with the leaf chamber for receiving air therefrom and for analyzing the air received.

Sampling systems provide apparatuses for obtaining and assessing the composition of a fluid, typically air. Sampling systems allow industrial hygienists to assess the risks and determine the protective equipment that should be worn by personnel entering a specific environment. In one embodiment, a sampling system comprises a sampling container that draws air into its inner volume and the sampling periods are controlled by an automatic timer valve. The automatic timer valve may comprise a rotating disk or plate that provides fluid communication from the area to be sampled to the inner volume of the sample bag when apertures are aligned with inlet tube.

A device and a method for gas or particle measurement in a portable electronic device. The portable device includes a housing which, with the exception of an overflow opening, has an almost gas- and air-tight design. A display unit, an operating unit, a transceiver unit, and optionally a power supply unit may be integrated into the housing in particular. Furthermore, the housing may also include the required electronics. By deflecting a movable outer wall of the housing with the aid of an actuator, the volume of the inner space of the housing may be increased or reduced. A gas exchange between the inner space and the space outside of the housing may thereupon take place via the overflow opening in the housing, and a possible substance, in particular, a predetermined gaseous component or a particle concentration may be analyzed in a gas flow during this gas exchange.

A method and apparatus are disclosed for assessing gas exchange of plants. The method includes receiving in a gas analyzer a plurality of test air samples from a leaf chamber corresponding respectively to first and second plant leaf samples received separately and in sequence in the leaf chamber while being exposed to light to form the first and second test air samples, the first and second test air samples being received in sequence in the gas analyzer as an integrated gas stream, and the gas analyzer analyzing the integrated gas stream as it flows therethrough. The measuring apparatus includes a leaf chamber for receiving therein a plant leaf sample to be tested, a pump communicating with the leaf chamber for supplying air thereto, and an analyzer communicating with the leaf chamber for receiving air therefrom and for analyzing the air received.

The disclosure relates to an analyzer which is configured to analyze a gas mixture for a specified substance. A tubular input unit can be connected to a main body. A gas mixture can be introduced into the input unit and flows from an inlet to an outlet. A fluid guide unit connects a suction opening in the input unit to a measurement chamber. A suction unit can suck in a gas sample from the input unit by suction and can convey it through the fluid guide unit into the measurement chamber. A sensor can measure the concentration of the substance in a gas sample located in the measurement chamber. A valve optionally opens or closes the fluid guide unit. An electrostatically charged and/or mechanically acting filter in the fluid guide unit is located between the suction opening and the valve.