The T300-RT-UV-VIS dip probe from Ocean Optics Inc. measures in situ UV-VIS-shortwave NIR absorbance and the transmission of chemicals, pharmaceuticals and other solutions. The probe can be embedded into process streams for real-time online sample monitoring. It features a configuration for optically dense or dilute solutions and epoxy mounting for chemical resistance. The probe consists of two 300-µm optical fibers in a 1.25-in.-outer-diameter stainless steel assembly that slides into a ferrule. Interchangeable probe tips are available with 2-, 5- and 10-mm optical path lengths.