Light Scattering Fundamentals
Twenty-four short modules on the things that actually go wrong at the bench, and the science underneath them. Each is five sections and a short quiz, with a completion certificate when you pass.
Training the next generation of particle characterization experts, helping customers every step of the way.
Dust: The Particle That Lied to You
Recognizing, diagnosing, and defeating dust contamination in DLS. The d⁶ problem, the Baseline Index, and not filtering away your own data.
Start module →Your Sample Is Too Concentrated and So Are You
Count rate, the NDF wheel, multiple scattering, and the radical idea that dilution makes data better.
Start module →Zeta Potential and the ±30 mV Threshold of Trust
Surface charge, colloidal stability, DLVO, the isoelectric point, and salt's double-edged role.
Start module →The Hydrodynamic Diameter Hoax
Why DLS reads larger than TEM, intensity vs. number vs. volume weighting, and reading PDI honestly.
Start module →When Your Zeta Potential Won't Sit Still
PALS vs. ELS, the reference beam, self-peaking, and the short checklist behind irreproducible zeta.
Start module →Why We Add Salt (No, Not for Flavor)
Ionic strength control, the Debye length, salting out, and filtering the stock you spike in.
Start module →Aligning the BI-200SM Without Crying
Toluene, the I·sin(θ) plot, vernier offsets, and not chasing dust with a screwdriver.
Start module →Rods, Disks, and the Particles That Refuse to Be Spheres
Anisotropic particles, multiple decay rates, Perrin equations, and the backscatter trap.
Start module →Static Light Scattering: Weighing Molecules With Light
Molecular weight, radius of gyration, Rg/Rh shape, the plot zoo, and the Debye 12 nm limit.
Start module →The APDx Detector: Counting Photons Without Lying About It
Dead time, the forgotten 25 ns setting, dark counts, detector aging, and the linear range.
Start module →The Case of the Sample That Wasn't There
Non-aqueous solvents, contrast matching, viscosity-unit traps, glass vs. plastic, and number fluctuations.
Start module →The Autocorrelation Function: Where Size Actually Comes From
Correlation decay, Γ = Dᵗq², the Siegert relation, cumulants vs. CONTIN, and reading the baseline.
Start module →The BI-ZTU Auto-Titrator: Automating Your Way to a Stable Formulation
Automated pH titrations, finding the IEP, additive optimization by zeta plateau, and the pump that won't prime.
Start module →Why Is My Zeta Potential Positive? A Sign-Reversal Mystery
Electrode orientation, the ZR5 check, surface potential vs. zeta, specific ion adsorption, and the IEP.
Start module →Conductance vs. Conductivity: A Distinction That Costs You Hours
µS vs. µS/cm, why the NanoBrook reports conductance, and reading it as a pre-zeta health check.
Start module →Temperature Equilibration: The Fifteen Minutes You Keep Skipping
Stokes–Einstein, equilibration times, convection faking diffusion, the 300 s default, and viscosity.
Start module →Cross-Correlation and Afterpulsing: Two Detectors, One Truth
The short-delay artifact, the two-detector cure, the honest 2D-vs-3D distinction, and DWS.
Start module →The Metal-Oxide IEP Ladder (and Why Mixing Them Is Dangerous)
IEPs from silica to magnesia, titration hysteresis, and the mixed-oxide hetero-aggregation trap.
Start module →The .bak Archive: Saving Data Your Future Self Won't Curse
Portable archives, the dual filtered/unfiltered ACF storage, and reporting honest significant figures.
Start module →Is the Laser Actually Dead? A Field Autopsy
Standby and shutter impostors, contrast-matched samples, the <1 mW death test, and the reference-beam early warning.
Start module →Is It the Detector? Diagnosing a Sick APD or PMT
Dark counts as a vital sign, aging and saturation, the connector that destroys PMTs, and laser-vs-detector triage.
Start module →Baselines, Intercepts, and Bad Fits
Calculated vs. measured baselines, autoslope misfires, the intercept as a health check, and reading a fit before trusting it.
Start module →Don't Break the Instrument: A Hardware Care Survival Guide
The interlock-free laser, the PMT-killing connector, the fingerprint-hating vat, the extinct cable, and safe module return.
Start module →Counting Without Counting: The Concentration Tool and Other Clever Tricks
Scattering as a concentration proxy, the dn/dc error doubler, the BI-870 nonpolar niche, and inference within assumptions.
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