Reflectance spectroscopy
Definition
Measurement of the proportion of incident light reflected from a surface at each wavelength. Absorbing chromophores (such as haemoglobin) reduce reflectance at their characteristic wavelengths, producing absorption features in the spectrum.
Related terms
- Haemoglobin spin state
- The electronic configuration of iron in the haem group, either high-spin or low-spin. Oxyhaemoglobin and methaemoglobin differ in spin state, and Raman...
- Near-infrared spectroscopy (NIR)
- Spectroscopic technique using wavelengths from approximately 700 nm to 2500 nm. NIR probes overtones of molecular bond vibrations (C-H, N-H, O-H) and...
- Principal component analysis (PCA)
- A multivariate statistical method used in fire debris research to reduce chromatographic data matrices to principal components that capture major variance. Used...
- Raman spectroscopy
- A non-destructive laser-based technique sensitive to molecular vibration modes in pigments; complements FTIR by characterising pigment molecular structure rather than bulk ink...
- Validation
- The process of establishing through systematic testing that a method does what it claims to do, within defined conditions and with a...
Explained in
- Spectroscopic Methods for Bloodstain AgeingMeasurement of the proportion of incident light reflected from a surface at each wavelength. Absorbing chromophores (such as haemoglobin) reduce reflectance at...