Devices and methods for rapidly and incrementally or continuously, measuring rheological properties of polymers under different shear rates. The device includes a pump configured to accept a continuous stream of sample solution during an interval of time, an injector configured to inject a flow of the sample solution through two or more viscometers, and a computing and processing device configured to monitor and measure rheological properties of the solution under at least two shear rates simultaneously in the two or more viscometers.