Digital refractometers offer automatic measurement of the refractive index and Brix scale.

Model RX-007[alpha] is designed for measuring water soluble samples with very low concentrations (5% or less), such as tea and low sugar beverages. It has a measurement temperature of 15 to 30°C (59 to 86°F). Models RX-5000[alpha], RX-7000[alpha], and RX-9000[alpha] are equipped with a Peltier thermo module for maintaining a constant measuring temperature. Measurement starts after the sample reaches the target temperature. Up to 30 user scales can be programmed on these models, and they also feature flash memory, which is capable of recalling the last 30 measured values. Model RX-5000[alpha] has a measurement temperature of 5 to 60°C (41 to 140°F). Model RX-7000[alpha] has wider measurement ranges than model RX-5000[alpha] and is suited for measuring samples that have a higher melting point, such as oils and fats, and samples that have a higher refractive index, such as perfumes and organic solvents. Model RX-7000[alpha] has a measurement temperature of 5 to 70°C (41 to 158°F).

Model RX-9000[alpha] offers the highest level of accuracy in all measurement ranges, and is suitable for a wide range of sample types, such as oils and fats with high melting points, aroma oils of high refractive index, and organic solvents. It has a measurement temperature of 5 to 70°C (41 to 158°F). Model RX-5000[alpha]-Bev is a re-designed version of model RX-5000[alpha], and is suitable for measuring beverages. A flat sample stage replaced the sample well to make it easier to wipe off the samples and to allow for faster and easier clean-up. Model RX-5000 is equipped with all standard features of RX-[alpha] series except built-in thermostatic module. Instead of that it includes nozzle for connection to a external water bath.

All models have a printer output, as well as a RS-232C output for connection to a computer.

Optional digital printer units automatically print out the number of samples, measurement value for refractive index (nD or nDt), Brix (%), concentration (%), and measurement temperature whenever the refractometer completes measurement. Model DP-RX is a thermal dot printer suitable for use with RX-7000[alpha] (serial no. 051301 onward). Model DP-RD is an impact dot printer suitable for use with all RX-[alpha] series refractometers.