Data sections

The FOSS Micral is a Laser-Induced Breakdown Spectroscopy (LIBS) instrument. Unlike the reflectance spectrometers, LIBS measures elemental emission intensities in the ultraviolet and visible range. It covers 178–427 nm at 0.1 nm resolution, producing 2491-element arrays of raw emission intensity values (not reflectance). LIBS ablates the sample surface with a laser pulse and records the resulting atomic emission spectrum.

Prerequisites

The foss micral provision must exist from Load utility data.

Notebook cell

In load_ai4sh_spectral_data.ipynb, the Manage LIBS spectrometer cell runs:

job_file = 'import_data/LIBS_spectra/job_libs_spectrometer.json'

structured_process_D, scheme_params_D = Initiate_process(notebook_path, scheme_file, job_file)

if structured_process_D is not None:
    Run_process(structured_process_D, scheme_params_D)

Job file

Path: ./ai4sh/import_data/LIBS_spectra/job_libs_spectrometer.json

{
  "process": {
    "job_folder": "import_data/LIBS_spectra/spectrometer",
    "process_sub_folder": "process",
    "pilot_file": "xspatula_add_spectrometer_pilot.txt"
  }
}

Process file

Path: ./ai4sh/import_data/LIBS_spectra/spectrometer/process/foss-micral_spectrometer.json

{
  "process": [
    {
      "process": "manage_spectrometer",
      "parameters": {
        "provision_id__provision_name": "foss micral",
        "wavelength_unit_id__wavelength_unit_name": "um",
        "wavelength_array": [178.0, 178.1, 178.2, 178.3, "...2491 values total...", 427.0]
      }
    }
  ]
}

The wavelength_array contains 2491 values from 178.0 to 427.0 nm in 0.1 nm steps. The example above is abbreviated.

Instrument summary

Property Value
Provision foss micral
Wavelength range 178–427 nm
Spectral resolution 0.1 nm
Number of bands 2491
Measurement type Emission intensity (not reflectance)
Use context Laboratory

Note on stored values

LIBS observations store emission intensity counts, not reflectance values in the 0–1 range. Intensity values are typically in the thousands. This is different from all other spectrometers in the AI4SH database, which store reflectance.

Next step

Proceed to Manage LIBS observation log.

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