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The field is Environmental Monitoring and the time is now!
Atmospheric CO2 concentration and temp. are worringly rising. Periods of low-water availability going to become commonplace in Mediterranean and other ecosystems. Scientists in Spain are simulating predicted increases in carbon dioxide and temperature and observing the effects on plants, in general, and, specifically, crops. To monitor and control environmental conditions they use a Microlink 751 data-acquisition unit which they connect to their PC's USB port.
[img]http://www.windmillsoft.com/acatalog/751.jpg[/iimg]

The plug-and-play Microlink comes with the Windmill ready-to-run software suite for Windows, which makes the device very easy to use. Each Microlink 751 can capture data from 16 sensors and probes of various types. It can also control digital switches and thus be used to open and close solenoid valves when conditions dictate.

The researchers grew their crops in temperature gradient tunnels containing measuring and control equipment. CO2 concentration was continuously monitored by an infrared gas analyzer. Ventilated temp. and humidity sensors and air probes connected to another infrared gas analyser were placed 60 cm above the plants. Quantum sensors were placed on top and inside each tunnel to record photosynthetically active radiation (PAR). All data was continuously recorded by PC using the Microlink 751 DAQ unit and the Windmill software.

Along with continuously logging data, the system controlled solenoid valves which kept open or closed one of two sets of CO2 cylinders supplying the gas to the elevated CO2 tunnel. When CO2 concentration decreased below a fixed level, signalling that one of the cylinder sets was exhausted, the corresponding valve was closed and that of the other set opened. The Microlink system also sequentially measured CO2 concentration at several places in the tunnels with the same infrared gas analyser. The Windmill program successively opened for a fixed time interval one of the six solenoid valves sampling the air in the tunnels.

A lot of of previous research on elevated carbon dioxide has been done in fully-controlled environments using constant-temp. and electric lighting. Plant behavior in the field frequently differs from that in such facilities. The Spanish researchers used the temp. gradient tunnels to more realistically simulate aspects of the effects of future enviromental change. Their near-field technique had the added benefit of being enormously cheaper than other similar experiments.

More info: http://www.microlink.co.uk/climate.html