Valveless Piston Metering Pumps from Fluid Metering provide precision fluid control for environmental monitoring, sampling and treatment applications. The low-current DC motor is ideal for extended 12/24-volt battery operation in remote locations. Their CeramPump uses one moving part — a rotating and reciprocating ceramic piston — to accomplish both pumping and valving functions without valves. The piston and mated liner are made of dimensionally stable, sapphire-hard ceramics that ensure long-term, drift-free accuracy of 1 percent or better for millions of maintenance-free cycles. The inert fluid path of ceramic and fluorocarbon is ideal for injection of concentrated tracer dyes and water treatment chemicals. Models are available in all standard voltages as well as low-current DC voltage, making them fit for remote field operation. 800/223-3388; www.fmipump.com.