Frequently asked questions

Most computers do not provide enough power through USB ports to charge the LI-600 satisfactorily. It may take longer than a full night to charge from a computer. We recommend using the charger provided with the LI-600 or another compatible quick-charger for the fastest charging.

No, it is not necessary to calibrate the sensors before using it for the first time. See the LI-600 Porometer/Fluorometer Quick Start Guide to learn more about taking your first measurement.

At this point, there is not a specific frequency we recommend for zero since we do not have enough long-term information, but early indications are that it is stable for many months. We recommend checking the zeroes if the instrument has not been used for months, or at the beginning of a new experiment campaign.

This is most likely an issue with one or more calibration parameters in your fluorometer. Therefore, check those parameters first. To do this, connect the LI-600 to the computer software and enable the Factory Calibration in the software (Figure 1‑1). Then go to the factory page (Figure 1‑2) and view the values for the fluorometer. Use the Automatic Factory Reset to update them, but you can also manually enter them, and then press ‘Calibrate’ to load them into the instrument.

Figure 1‑1. In the drop-down menu on the Toolbar, select About Instrument then check the Factory Calibration box.
Figure 1‑2. Select the drop-down menu again then the Factory Calibration should show up.
To get reliable stomatal conductance readings, the chamber must be completely covered and sealed. However, if a fluorometer is equipped, you can take fluorescence measurements without filling the chamber.
No, it only measures stomatal conductance and transpiration, in addition to fluorescence. A CO2 measurement would be required for carbon assimilation. See the full list of the LI-600 parameters measured and calculated here. The LI-6800 Portable Photosynthesis System, however, can measure carbon assimilation, in addition to other parameters.
The instrument does not require the use of chemicals nor a daily calibration. We recommend periodically zeroing the LI-600 (see “How frequently do you recommend zeroing the RH and Flow sensors?”). Any small offsets due to temperature, dust, etc. will be taken care of by automated matching of the RH sensors.
No, the LI-600F is a PAM chlorophyll a fluorometer optimized for assessing the quantum efficiency of PSII. The fluorescence detection wavelength range is ~700 to 780 nm. There is some PSI fluorescence included in this signal, like similar fluorometers (6800-01A, for example).
Yes. If the clamp cannot fully seal onto the gasket, the leaf may be too thick for successful measurement. In practice we have found this limit to be 1-2 mm.
Models with a serial number of PFA-00553 and above have a GPS receiver. Coordinates for each measurement are recorded in the data file.
Comma-separated or tab-delimited text files. The option is set for each configuration in the LI-600 software preferences.
Eight hours of continuous use, typically. The LI-600 can also be charged by a portable battery pack connected to the micro-B USB port.
No, the LI-600 does not have dark-adapting clips.
No, the first generation of the LI-600 cannot be upgraded to add those components.