The PB-950 is a four-station jartester featuring four operator-programmable memory banks. Each bank can be programmed with paddle speeds from 5 to 300 rpm in 1-rpm increments, and run times from 1 second to 100 minutes in 1-second increments. The stirrer can be run sequentially through the memory banks, independently in any one of the memories, or continuously at a selected speed. Turning the stirrer off does not erase the programmed information. The PB-950 permits automatic transitioning from a fast mix/short run to a slow mix/long run, or any combination of speeds and times desired to most realistically duplicate actual plant conditions and operation. The PB-950 four-paddle portable jar testing station is built on a rugged, powdercoated steel uniframe chassis. A fluorescent lamp floc illuminator is built into the jartester base. Stainless steel 1" x 3" paddles are adjustable to a maximum depth of 9", and are spaced 6" apart. An electronic motor control system offers regulated variable speeds of all paddles simultaneously, from 1-300 rpm, displayed via digital readout. Comes complete with a choice of either four standard round glass 1-liter laboratory beakers or four B-KER square acrylic 2-liter jartesting jars, a dustcover and a one-year manufacturer's warranty. 120V models shown; call for other electronic configurations.