Changing Seasons With Your Eddy Covariance System: Tips and Tricks
It is good practice to give your instrumentation routine maintenance as the seasons change.
Below is a list of tips to help keep your Eddy Covariance System running in top shape.
Gas Analyzers: LI-7500A/RS/DS and LI-7200/RS CO2/H2O Analyzers
Check your software version and update to the latest instrument software, if necessary. Go here to update LI-7500A/RS/DS software, or here for LI-7200/RS software.
Check when the analyzer was last factory-calibrated, noting the recommended frequency.
Replace the internal chemicals once each year. If your instrument is in a humid environment, replace the chemicals every six months. Replacement instructions can be found here for the LI-7500A/RS/DS, and here for the LI-7200/RS.
Clean the optical paths. Cleaning instructions can be found here for the LI-7500A/RS/DS, and here for the LI-7200/RS.
With an LI-7200/RS, clean or replace air filters, as described here.
For locations with high seasonal temperature changes, consider whether you want to change the chopper housing temperature setting to save power, as described here. Note that if the chopper housing temperature is switched, a zero and two-point span must be performed.
If you have access to calibration gases, check the zero and span of the analyzers. Calibration instructions can be found here for the LI-7500A/RS/DS, and here for the LI-7200/RS.
Check all mounting hardware and cable connections to ensure they are intact and secure. In extremely humid environments, check and replace desiccant pack in the LI-7550 (for non-DS); click here for more information.
Gas Analyzer: LI-7700 Open Path CH4 Analyzer
Check your software version and update to the latest instrument software, if necessary. Go here to update the LI-7700 software.
Check the Optics RH in the main window of the interface software and change the internal desiccant if the indicator is red. Refer to the manual for more information.
Clean the optics and fill the washer with windshield washer fluid, as described in the LI-7700 instruction manual.
If you have access to calibration gases, check the zero and span of the analyzer. Refer to the manual for more information.
Check the recalibration frequency recommended by the sensor manufacturer, and follow their recommendations. Typically, radiation sensors and soil heat flux plates should be recalibrated every two years.
Check and clean the sonic anemometer and radiation sensors as needed. Use only mild detergents and clean water with optical-grade, lint-free cloths. Ensure radiation sensors are level. Four-component net radiometers may have drying cartridges which need replacement every 2 years. Heated ventilated net radiometers have dust filters which should be cleaned every 6 months or 1 year.
Check temperature/humidity probes and replace the filter if necessary, according to the manufacturer’s instructions.
Check the integrity of the mounting structure and all mounting hardware and cable connections. Check filters in ventilation units and clean or replace.