Baseline error

{
  "id": "MLC-T-CHM-001128",
  "term": "Baseline error",
  "field": "Chemistry",
  "definition": "A systematic error in a spectrometric reading that arises when the two light paths of a double-beam instrument transmit unequal power and this is not corrected, for example because the sample and reference cells are not matched. It appears as an offset of the whole spectrum from zero absorbance. It can be measured with both cells filled with the same solvent and then subtracted.",
  "subject": "Analytical Chemistry",
  "see_also": [
    "power",
    "spectrometer"
  ],
  "references": [
    "PAC, 1988, 60, 1449. 'Nomenclature, symbols, units and their usage in spectrochemical analysis - VII. Molecular absorption spectroscopy, ultraviolet and visible (UV/VIS) (Recommendations 1988)' on page 1456 (https://doi.org/10.1351/pac198860091449)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/baseline-error/"
}