Quantum sensors were placed on top and inside each tunnel to record photosynthetically active radiation (PAR); data was continuously recorded by computer using the Microlink 751 and Windmill software
Atmospheric carbon dioxide concentration and temperature are rising.
Periods of low water availability are expected to increase in Mediterranean and other ecosystems.
Researchers in Spain are simulating predicted increases in CO2 and temperature and investigating the effects on crops.
To monitor and control environmental conditions they use a Microlink 751 data acquisition unit which they connect to their PC's USB port.
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.
Carbon dioxide concentration was continuously monitored by an infrared gas analyser.
Ventilated temperature and humidity sensors and air probes connected to another infrared gas analyser were placed 60cm above the plants.
Quantum sensors were placed on top and inside each tunnel to record photosynthetically active radiation (PAR).
All the data was continuously recorded by a computer using the Microlink 751 Daq unit and the Windmill software.
As well as 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 programme successively opened for a fixed time interval one of the six solenoid valves sampling the air in the tunnels.
Much of previous research on elevated CO2 has been done in fully-controlled environments using constant temperature and electric lighting.
Plant behaviour in the field frequently differs from that in such facilities.
The Spanish researchers used the temperature 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.
The Microlink is extremely quick to install and easy to use.
However, should users have any problems Biodata provide free technical support for life.
Established 1973 in Manchester (UK), Biodata specialises in PC-based data acquisition and control systems.
All products are manufactured to IS0 9001-2000 standards.
