The STH and STQ Duplex metering pumps from Fluid Metering Inc, Syosset, NY, are designed for precision mixing, diluting, and proportional metering in original equipment manufacturer medical and analytical instrumentation. Consisting of two valveless pump heads directly coupled to a single variable stepper motor drive, the pumps serve as an alternative to conventional syringe pumps, which require multiple syringes, valves, actuators, and drivers. The displacement of each pump head is independently adjustable. In addition, a variety of pump head sizes can be used together to provide dispensing ratios from 1:1 up to 500:1, in units from microliters to liters.

Using the company’s CeramPump valveless piston pumping technology, a sapphire-hard ceramic piston represents the only moving part in the fluid path, performing both pumping and valving functions. The pumps provide continuous fluid dispensing and metering during maintenance-free cycles, within 1% precision, without recalibration. Unlike syringe pump designs that fill and dispense through the same single port, the pumps offer unidirectional continuous flow, increasing throughput by utilizing two separate ports for input and output. For more information, visit Fluid Metering.