The duoPUR consists of two quartz distillation units. Each unit contains two infrared heating elements (1), a water cooled condenser (2), a high-purity PFA collection bottle (3), and a fully automatic acid loading/discharge system. The vaporized liquid is collected on the inclined water-cooled condenser and drips into the collection bottle. The distillation process is microprocessor controlled, allowing the user to set the distillation time and power level by using a compact control terminal with easy-to-read, bright, full-color, touch-screen display. The distillation rate ranges from 50 to 400 mL per hour, depending on the power setting and the temperature of the cooling water.