Spectroscopy
Interactive
Beer's Law Calculator
A = ε·b·c live: read absorbance and %T from concentration, path length and molar absorptivity — then add stray light and a polychromatic beam to see real calibration curves bend from the ideal line.
Open model → InteractivePhotometric Error
Why measurement precision depends on where you read: relative concentration error vs absorbance across the three noise regimes, and the optimal-absorbance sweet spot near A ≈ 0.4.
Open model → InteractiveCalibration Methods
External-standard vs standard-addition on one plot: fit standards, recover an unknown, and watch a matrix effect bias one method while the other still lands on the truth.
Open model → InteractiveTransmission Fitting (TFit)
The capstone: fit the transmission model instead of taking log(I₀/I) and get hyperlinear absorbance — a straight line over a 10,000× range where the classic methods roll off.
Open model →