LI-7500A Frequently Asked Questions
Q What is the power consumption for the LI-7500A?
A The LI-7500A can be powered using any 10.5 to 30 volts DC power supply, such as a 12 volt car battery. During normal operation the analyzer uses only 12 Watts of power, making it a low power CO2/H2O gas analyzer for Eddy Covariance applications. With the ability to be powered by solar panels, the LI-7500A is ideal for use in remote locations with limited electrical power.
Q Is an upgrade available from the current LI-7500 to the LI-7500A?
A Yes! The 7500-650 upgrade kit is a field-installable package that includes parts for the sensor head upgrade, the LI-7550 Analyzer Interface Unit, and software updates.
Q What kind of data logger is necessary for measurements?
A The LI-7550 Analyzer Interface Unit allows collection of synchronized CO2/H2O, sonic anemometer or auxiliary data. Data are stored on a removable USB device. Additional outputs include Ethernet, high speed digital to analog converters, SDM, and RS-232 outputs which enable integration with a variety of data storage devices.
Q How much data can be stored in the LI-7550 Analyzer Interface Unit?
A An industrial grade 4 GB USB flash drive is standard and stores approximately 20 days of 10Hz data (logging the full compliment of data). The 4GB drive can log up to 50 days of data by logging only 10 variables. An optional 16 GB industrial grade USB flash drive is also available, which can provide up to 80 days of 10 Hz data (part number 616-10723). Larger storage devices, such as USB hard drives (>1 TB) can be used with power supplied from an external source.
Q Since the LI-7500A has integrated data logging, can I connect a sonic anemometer to it?
A Yes! There are four analog inputs on the LI-7550 Analyzer Interface Unit allowing wind speed in three dimensions and sonic temperature to be recorded with CO2 and H2O data.
Q What are the main differences between the LI-7500 and the LI-7500A?
A The LI-7500A offers a low chopper motor housing set point temperature for use in cold climates. This saves energy and essentially eliminates the impact of surface heating on CO2 flux measurements. The LI-7550 Analyzer Interface Unit gives high speed analog inputs for auxiliary sensors including a sonic anemometer. On board USB data logging as well as Ethernet connectivity allow for remote setup and easy data transfer. Longer data/sensor head cables (5 meters) and an optional sensor head cable extension make the LI-7500A ideal for mounting on eddy covariance flux towers.