Data file structure

After a data file is exported from the computer software as a tab-delimited or comma-delimited text file, it can be imported into a spreadsheet application. Data are organized into groups as indicated in the first row. The second row contains the data label, and the third row contains additional information such as unit, format, or equation.

The fluorometer, leaf angle, and GPS groups will be absent from the data files of LI-600 models without those features.

Variables, units, and equations

To view a variable's unit of measure, format, or equation, see the third row of the data table as imported into a spreadsheet application. The example below shows information in the fluorometer configuration group.

Figure 6‑1. Variables and their equations and units in the fluorometer configuration group.

Groups, labels and descriptions

Following is a list of groups and labels in each data file, and the description for each label. See Flash files for information on flash files. The tables are organized as follows.

label Description


The System group consists of five parameters for each measurement. Time and Date are set manually in Settings or synced from GPS (recommended) on the device. See Instrument Settings and Clocks.

Obs# Observation/record number
Time Time of observation: HHMMSS
configName Configuration name
configAuthor Configuration author

User Defined

The User Defined group contains the remarks and labels created in Configuration Management in the computer software. See Remarks and Data Labels for configuring them. See Taking a measurement for adding them to measurements. At least one label must be formatted as a barcode to enable the barcode scanner.

remark Mark reason -alphanumeric
barcode Label 1 barcode, list, or number
  Label 2 barcode, list, or number
  Label 3 barcode, list, or number


The Porometry Group contains the data collected from the LI-600 porometer. See Porometry group.

gsw Stomatal conductance
gbw One-sided boundary layer conductance
gtw Total conductance
E_apparent Transpiration
VPcham Chamber vapor pressure
VPref Reference vapor pressure
VPleaf Leaf vapor pressure
VPDleaf Vapor pressure deficit
H2O_r Reference H2O mole fraction
H2O_s Chamber H2O mole fraction
H2O_leaf Leaf H2O mole fraction
leaf_area Leaf area in cm2


The Fluorometry Group contains the data collected from the LI-600 Fluorometer. See Fluorometry group.

flashID Flash file ID
Fo Minimum fluorescence in dark
Fm Maximum fluorescence in dark
Fv/Fm Quantum efficiency in dark
Fs Minimum fluorescence in light
Fm' Maximum fluorescence in light
PhiPS2 Quantum efficiency in light
PS2/1 Ratio of PSII to PSII absorptance
abs Leaf light absorptance
ETR Electron transport rate


The Sensor group contains the values recorded by the relative humidity, temperature, flow, pressure, and PAR sensors as well as the battery voltage. The output in the SENSOR group is calculated from the SENSOR_V and calibration coefficients determined at the factory. See Sensor calculations for the equations.

rh_s Sample relative humidity
rh_r Reference relative humidity
Tref Block reference temperature
Tleaf IRT leaf (sample) temperature
P_atm Atmospheric pressure
flow Flow rate to cuvette
flow_s Exhaust flow leaving cuvette
leak_pct Flow percent leak
Qamb Ambient light
batt Battery voltage

Leaf angle

The leaf angle group contains measurements from the magnetometer, accelerometer, GPS, and calculated variables. See Leaf angle and GPS. This group will not be included in data files from instruments without an accelerometer/magnetometer.

pitch Slope from horizontal
roll Rotation from horizontal
heading Rotation from North
angle_inc_leaf Angle of incidence between the leaf and the sun
direct_pct Proportion of direct irradiance incident on leaf
slope_leaf Leaf inclination from horizontal
az_leaf Leaf rotation from south
dec_solar Angular position of sun with respect to equator
az_solar Solar rotation
zenith_solar Solar zenith angle


The GPS group contains the GPS coordinates, altitude, number of satellites, and horizontal dilution of precision. For important information about GPS time, see Clocks. This group will not be included in data files from instruments without a GPS receiver.

gps_time YYYYMMDD
gps_date HHMMSS
latitude Latitude
longitude Longitude
altitude Altitude (meters)
gps_sats Number of gps satellites
gps_HDOP Horizontal dilution of precision


The Match group records the time and date of the RH sensor matching and the sensor correction. See Matching RH sensors for the equations, Measurement Settings, and Taking a measurement.

match_time Match time
match_date Match date
rh_adj Relative humidity sensor correction


The Stability group records the measurement stability of stomatal conductance(gsw), and slope and fluorescence (flr) at 1, 2, and 4 seconds. See Taking a measurement, step 6, and for the equations.

gsw1sec Stomatal conductance at 1 sec
gsw2sec Stomatal conductance at 2 sec
gsw4sec Stomatal conductance at 4 sec
flr1sec Slope and fluorescence at 1 sec
flr2sec Slope and fluorescence at 2 sec
flr4sec Slope and fluorescence at 4 sec

Porometer configuration

See Measurement Settings.

auto Auto mode
flow_set Flow set point
gsw_limit gsw slope limit
gsw_period gsw period

Fluorometer configuration

See Measurement Settings.

dark Dark adapted or not
flash_type Flash type
flash_intensity Flash intensity
modrate Modulation rate
flr_limit Flr slope limit
flr_period Flr period
P1_dur MPF phase 1 duration
P2_dur MPF phase 2 duration
P3_dur MPF phase 3 duration
P1_Fmax Phase 1 maximum fluorescence
P2_ramp Phase 2 ramp depth
P2_slp Phase 2 regression slope
P3_Fmax Phase 3 maximum fluorescence
P3_Pred Phase 3 predicted fluorescence
P3_DeltaF Phase 3 measured–phase 3 predicted

Sensor voltage

The Sensor Voltage group reports the voltage for each of the sensors. The output in the SENSOR group is calculated from the SENSOR_V values and calibration coefficients determined at the factory. See Sensor calculations.

v_humA Reference RH sensor (poro)
v_humB Sample RH sensor (poro)
v_flowIn Inlet flow sensor (poro)
v_flowOut Outlet flow sensor (poro)
v_temp Thermistor (poro)
v_irt IRT target temperature (poro)
v_pres Pressure sensor (poro)
v_par Quantum sensor (poro)
v_F De-modulated fluorescence (fluoro)
i_LED LED current (optional) (fluoro)

User calibrations

See User calibration procedures, Calibrating the sensors, and Drop-down menu.

b_rhr Ref RH sensor zero intercept (poro)
m_rhr Ref RH sensor slope (poro)
span_rhr Ref RH sensor span (poro)
b_rhs Sam RH sensor zero intercept (poro)
m_rhs Sam RH sensor zero slope (poro)
span_rhs Sam RH sensor span (poro)
z_flowIn Flow in zero (poro)
z_flowOut Flow out zero (poro)
z_quantum Quantum sensor zero (poro)
z_flr Fluor zero (optional) (fluor)


The metadata for each measurement includes instrument and sensor serial numbers, embedded firmware version, and when the configuration was last updated. Metadata for each data file can be viewed in the LI-600 computer software. See Local Files.

flashId Flash ID (fluoro)
lciSerNum Instrument serial#
lcpSerNum Porometer serial#
lcfSerNum Fluorometer serial#
lcrhSerNum RH sensor serial number
version Embedded version
configUpdatedAt Configuration update date

Flash files

Flash files are fluorometer data files. If a data file contains fluorometer measurements, a flash file for each measurement is downloaded and included in the .zip file exported from the computer software. See Measurement Settings, Rectangular flash, and Multiphase flash.

Flash Files
flashId Flash file ID
lciSerialNumber Instrument serial#
lcpSerialNumber Porometer serial#
lcfSerialNumber Fluorometer serial#
Fm Fm
Fo Fo
Fv/Fm Fv/Fm
Fm' Fm'
Fs Fs
LightIntensity Light intensity