Small angle X-ray scattering (SAXS) instruments are used to determine nanoparticle size distributions, pore sizes, the shape of macromolecules, and characterize distances in materials. This is performed by analyzing the elastic scattering of X-rays that travel through the sample material and recording their scattering at small angles. Typical applications include biological macromolecule, protein, and material characterization. Key considerations include temperature range, detector type, measuring time, X-ray generator, and particle size.