Measurement of latex microparticle size by dynamic speckle technique

•Temporal evolution of speckle patterns is used as an non-invasive and low-cost technique for sizing dielectric microparticles.•A direct experiment on speckle patterns of a drying aqueous drop of standard latex microparticles was conducted.•Overall experiment constitutes a proof of concept of the direct application of the speckle phenomena to microparticle sizing.