John Morris Scientific has introduced LI-Cor's LI-7500 open path CO2/H2O infrared gas analyser, which accurately measures absolute densities of carbon dioxide and water vapour in turbulent air.
In the eddy covariance method, these measurements are used in conjunction with sonic anemometer data to determine fluxes of CO2 and H2O from agricultural or natural landscapes such as forests, grasslands, deserts and oceans for global change and ecological studies.
The LI-7500 gas analyser has a sealed sensor head with sapphire optical windows allowing operation in harsh environments at temperatures ranging from -250C to +500C.
The lightweight sensor head can be mounted in any desired orientation.
The open path measurement eliminates the need for a pump, reducing the overall power requirement of the flux system.
This can be important in remote locations where electrical power supply may be limited.
The open path analyser also eliminates time delays, pressure drops and sorption/desorption of water vapour on tubing employed with closed path analysers.
The LI-7500 comes with Windows software for setup, calibration and monitoring.
The software has a user-programmable delay time feature to synchronise CO2 and H2O with data from sonic anemometers.