Specifications include, but are not limited to: Purchase of LI-6800 Portable Photosynthesis System. LI-COR, Inc. manufactures a portable photosynthesis system, LI-6800, capable of measuring CO2 and H2O concentrations in the sensor head, measuring H2O with an infrared gas analyzer, maintaining low CO2 signal noise, containing a user-cleanable optical bench, having a chamber temperature control range of plus or minus 10 degrees Celsius, with a thin film transistor LCD touch screen, a red/blue light source with high uniformity over 90% of the aperture, remote control of the instrument, and high flow rates at STP. This instrument is a LI-6800P portable photosynthesis system, and no other company produces an instrument with these specifications or capabilities. The Ll-6800 is the only system on the market with the following capabilities, all of which are essential in making high quality measurements of photosynthesis and providing students with access to stateof-the-art technology that will enhance laboratory and independent research projects. • The instrument's CO2 and H2O infrared gas analyzers are located in the sensor head, so gas concentrations are measured within the leaf cuvette mixing volume. Gas samples are not pumped from the leaf cuvette through hoses and filters before analysis, so there is no time delay to confound correlations between gas exchange and changes in environmental driving variables. • H2O is measured with a highly precise infrared gas analyzer, rather than a capacitance relative humidity sensor (common in other photosynthesis systems) • The gas analyzer CO2 signal noise is low (s0.1 µmol moI-1 RMS at 1Hz) with 4 second averaging at 400 µmol moI-1 , providing high accuracy measurements • The optical bench is user cleanable, thus avoiding costly returns of the system to the factory for cleaning • The chamber temperature control range is ±10°C relative to ambient conditions, making research questions relevant to changing climate easily addressed in a classroom/laboratory setting • The system has a sunlight readable thin film transistor LCD with capacitive touch screen for ease of use in the field • The system's red/blue light source has uniformity of ±10% over 90% of the aperture, enhancing measurement quality • The instrument's configuration and data acquisition can be remotely controlled through Ethernet connection and projected, enabling ease of use in a classroom setting • The system has a user settable chamber overpressure option • System flow rates of up to 1700 tmol s1 at standard ambient temperature (25°C) and pressure (100kPa) are achievable.