Fluid Metering, Inc. (Fluid Metering) has added STH and STQ Ratio:Matic® Duplex pumps to its line of products. These pumps are ideal for precision mixing, diluting, and proportional metering for OEM medical, analytical, and industrial instrumentation. Ratio:Matic® pumps are made up of two FMI valveless pump heads direct coupled to a single variable speed drive. The displacement of each pump head can be adjusted independently, and numerous pump head sizes can be used in combinations to attain dispensing ratios from 1:1 up to 500:1. Each pump head is calibrated at the factory, locked in place, and will not require recalibration in the field, even after countless cycles. Fluid Metering also carries models that can be adjusted in the field for applications that require frequent changes in mixing ratios or dispense volumes. The Duplex Ratio:Matic® OEM Pumps feature FMI’s CeramPump® valveless piston pump technology. This innovative pump design uses one moving part, a rotating and reciprocating ceramic piston, to carryout both pumping and valving functions without valves. Made of dimensionally stable, solid ceramics, the piston and mated liner feature long term, drift-free accuracy of 1% or better for millions of maintenance-free cycles.