Move the pointer over the plot to read wavelength and each displayed spectrum.
Combined spectral data table
One wavelength column and one column per spectrum. Only values at each spectrum's recorded wavelengths are shown; gaps and unavailable derivatives remain blank.
Spectral readings & wavelength lookup
Inspect original readings or derivatives D1–D4 at measured wavelengths. Linear interpolation is identified and never crosses missing-data gaps.
Wavelength (nm)
Signal value
Provenance
05 / Export displayed numerical values
CSV defaults to original wavelength positions without filling missing readings. The aligned option labels measured, interpolated and unavailable values per curve. Each CSV records the app version, processing range and fitting parameters.
06 / Analytical measurements
Researcher-selected interval; candidate extrema and zero crossings are numerical features, not chemical identifications. Derivative amplitudes depend on fitting parameters.
07 / Non-destructive spectral processing
A processed curve is added without overwriting measurements. Processing uses your explicit derivative processing interval, retaining measured wavelength positions.
Absorbance, A = −log₁₀(T), is dimensionless; this relation applies to absorbance data, not to every normalized or ratio signal. For a dimensionless ordinate differentiated n times with respect to wavelength in nm, the derivative has units nm⁻ⁿ; other signal units are retained and multiplied by nm⁻ⁿ. Derivatives are estimated by local polynomial fitting at the recorded wavelengths, rather than by differentiation of an exact continuous spectrum. Their amplitudes and zero crossings depend on noise, sampling, polynomial degree, fitting-window width and boundary treatment, particularly at higher orders. Extrema, zero-crossing candidates, integrated areas and spectral overlays are numerical or graphical descriptors whose interpretation requires suitable controls and experimental context. Original measurements are preserved; missing-data gaps are not bridged in the plotted curves, and any interpolation in an aligned CSV is explicitly identified. Analytical selectivity, analyte identity and method validation require independent experimental evidence. PNG dimensions and DPI describe export settings; SVG preserves vector geometry independently of raster resolution.