LI-COR LI-7815, Instruction Manual

Page: 35 / 98

Components of the data file
The text file will include a file header, data header, and data.
File header
The file header provides information about the instrument that measured the data.
Header Label Description
Model The model of the instrument
SN The serial number of the instrument
Software Version The software version on the instrument
Timestamp The date and time of the beginning of the requested data (according
to the instrument clock; yyyy-mm-dd hh:mm:ss).
Timezone The timezone setting on the instrument when the data is requested.
Data header
The data header identifies the columns of values that are in the file. You'll see two
rows: one called DATAH, which gives the variable names for the corresponding
columns, and one called DATAU, which gives the units for the corresponding
columns.
DATAH DATAU Description
SECONDS secs Seconds past the universal epoch (Unix time).
NANOSECONDS nsecs Nanoseconds of the seconds
NDX index A count of scans. At four scans per second, the value
increases by four counts per second.
DIAG diag Diagnostic code (see Status codes on page 2-9)
REMARK - The remark entered in the
Remark
field
DATE date Date of the record in yyyy-mm-dd
TIME time Time of the record in HH:MM:SS (according to the
instrument clock)
H2O ppm Water vapor concentration
CO2 ppm Carbon dioxide mole fraction in dry air
CAVITY_P kPa Optical cavity pressure (typically near 39)
CAVITY_T °C Optical cavity temperature (typically near 55)
LASER_PHASE_P kPa Laser phase pressure
LASER_T °C Laser temperature
RESIDUAL n/a Difference between raw and best fit spectra
Section 3. Applications of the LI-7815
3-5 Components of the data file