Month: February 2023

We often use refractometers to measure total dissolved solids (TDS) of coffee, but these instruments don’t measure TDS directly. Instead, they measure the refractive index of the liquid—a characteristic related to the speed of light in the liquid—and then estimate TDS using an empirical relationship between refractive index and TDS. This relationship between refractive index… Continue reading Estimating TDS from Refractive Index

Introduction A little while back, DiFluid sent me a pre-production version of their R2 Extract refractometer. Since then, these units have gone to production, and DiFluid kindly sent me one of the production units as well. One of the things I like most about the R2 Extract is that it displays temperature and refractive index… Continue reading Validating the DiFluid R2 Extract