LI‑7200RS Frequently Asked Questions
Q Can I upgrade my LI‑7200 to an LI‑7200RS?
AYes. Any LI‑7200 can be upgraded. The upgrade includes new hardware and a factory recalibration. You must send your instrument to LI‑COR for the upgrade.
Q What effects will precipitation have on my data set, especially if I leave an instrument deployed over a long period of time?
AThe LI‑7200RS provides continuous measurements during precipitation events. This makes the instrument well suited for field sites with frequent precipitation.
Q What kind of pump should I use for the LI‑7200RS?
AWe recommend the 7200‑101 Flow Module. The 7200‑101 draws air through the sample path at up to 15 LPM with low power consumption. It is configured through the analyzer software and flow data are logged with the data set.
Q How often does the instrument need to be calibrated?
AUser calibration can be performed once per month or less frequently. No specific time interval is set for factory recalibration. You can determine if the instrument needs to be recalibrated by checking the zero and span at two points. If measurements are not correctable by setting the zero and span, a factory recalibration may be needed.
Q What kind of data logger is necessary for measurements?
AYou don’t need an external data logger to record data from the LI‑7200RS. The LI‑7550 Analyzer Interface Unit collects synchronized CO2/H2O densities, sonic anemometer measurements, and supporting ancillary data from a LI‑COR Biomet System on a removable 16 GB USB device.
Q What is the power consumption of the LI‑7200RS?
AThe LI‑7200RS can be powered from any 10.5 to 30 VDC power supply. The instrument typically uses 12 watts of power. With the 7200‑101 Flow Module, it uses about 30 watts. The LI‑7200RS can be powered from a solar power system, making it suitable for use in locations with limited power.
Q What are the advantages of the LI‑7200RS for pCO2/DIC measurements?
AThe instrument’s rigid source filament is not susceptible to low frequency vibration, which may occur on ship deployments. It has a CO2 calibration range from 0‑3000 ppm and an H2O range from 0‑60 ppt. Cleaning the optical bench is simple and requires no special tools. These features make the LI‑7200RS useful for pCO2 and DIC measurements.
Q How short can the intake tube be?
AThe instrument is designed to mount on a tower, close to the sonic anemometer. We recommend using a ½‑ to 1‑meter long intake tube. The included intake tube can be cut to the desired length. The 71 cm heated intake tube should not be shortened.
Q Are there any consumables with the LI‑7200RS?
AThe LI‑7200RS requires three internal chemical bottles to scrub CO2 and H2O out of the instrument. These need to be replaced on a yearly basis to maintain the accuracy of the instrument. Replacement chemical bottles can be purchased pre‑filled from LI‑COR (part number 7200‑950).
Q Does the LI‑7200RS require an intake filter?
AWe recommend an intake filter if the air is dirty with dust, pollen, or other fine contaminants. Two 2‑micron Swagelok filters are included with each instrument. The filters are compatible with both the insulated and heated intake tubes. No filter is needed if the air is clean, however, the use of a filter can reduce site maintenance requirements.
Q Does the instrument need to be recalibrated after cleaning the optical components?
AWe recommend that you check the instrument zero and span after opening the optical cell. A factory calibration is not required.
Q How much data can be stored in the LI‑7550?
AThe instrument includes one 16 GB industrial grade USB drive. It can store up to 64 days of 10 Hz eddy covariance data when logging all 34 variables from the LI‑7200RS. Ten to fifteen variables will be logged in a typical application, in which case data could be logged for 128 days with the 16 GB flash drive.
Q Since the LI‑7200RS has integrated data logging, can I connect a sonic anemometer to it?
AYes. There are four analog inputs on the LI‑7550, allowing for wind speed in three directions and sonic temperature to be recorded with CO2 and H2O data. We provide data cables for some Gill and Campbell Scientific anemometer models.