a portable fast analyzer is provided that uses a magnetic clutch / brake to rapidly accelerate the analyzer rotor , and employs a microprocessor for automatic analyzer operation . the rotor is held stationary while the drive motor is run up to speed . when it is desired to mix the sample and reagent , the brake is deenergized and the clutch is energized wherein the rotor is very rapidly accelerated to the running speed . the parallel path rotor that is used allows the samples and reagents to be mixed the moment they are spun out into the rotor cuvetes and data acquisition begins immediately . the analyzer will thus have special utility for fast reactions .