Technology
How the measurement actually works
Written for the people who will be asked to defend the method internally: what mid-IR sees, why transmission beats a probe surface in dense media, what a chemometric model does, and how a shared-cavity dual comb replaces a delay stage.
Mid-infrared spectroscopy
Why molecular bonds absorb where they do, and what that makes measurable.
ReadTransmission versus ATR
Why a transmission measurement reads opaque and viscous streams that a probe surface cannot.
Chemometrics & calibration
How a spectrum becomes a concentration, and how many samples that takes.
Residence time distribution
What RTD is, how a tracer experiment is run, and what the curve tells you.
ReadDual-comb & ASOPS
How two pulse trains from one cavity replace a mechanical delay line.
Quantum cascade lasers
The mid-IR source technology and what it enables in a palm-sized instrument.
Why these pages exist
Because the decision to put an analyser on a process is almost never made by one person. Somebody has to defend the choice to a colleague who will ask why not Raman, why not NIR, why this path length, why a flow cell rather than a probe, and what happens when the water background shifts with temperature.
These pages are written to be forwarded and argued with. They teach the technique first and mention the instrument last, and the numbers in them are checkable.
The explainers
Three published, four in draft. Ask if you need one of the later ones now and we will send it.
Mid-infrared spectroscopy
What the region measures, the fingerprint region, Beer's law, and why water is the recurring difficulty.
ReadResidence time distribution
Danckwerts, the E-curve, the moments, and what the shape of the tail is telling you.
ReadDual-comb & ASOPS
Two combs, one cavity, and a delay axis with nothing that moves.
ReadTransmission versus ATR
Why a surface measurement and a bulk measurement answer different questions. In draft.
Chemometrics & calibration
PLS, preprocessing, and why cross-validation must be blocked by batch. In draft.
Quantum cascade lasers
Where QCL sources sit against thermal sources in the mid-IR. In draft.
Need to defend the choice internally?
Tell us the objection you are getting and we will send the page — or write the answer if it does not exist yet.