DéscriptionThe FLV400 Series Controller accurately measures and controls liquid flows. The sensors are matched to the servo valve for each of the ranges to be covered up to 2 l/min in liquids. A linear electrical output signal is provided for recording data. These controllers eliminate the need for continuous monitoring and readjustment manually of gas or liquid pressures to provide a stable fluid flowrate. The heart of the FLV400 is the flow sensor, which uses a Pelton-type turbine wheel to determine the flowrate of the fluid. Rotation rate of the turbine wheel is linear over a wide dynamic range. The electro-optical system consists of a diode emitting energy in the infrared spectrum. Light energy is alternately reflected and absorbed from “spokes” deposited upon the small turbine wheel. Such reflected light energy is detected by means of a photo diode. Thus, as the turbine wheel rotates in response to fluid flowrates, electrical pulses are generated. Processing circuitry provides a dc voltage output proportional to the flow rate. A bi-directional linear stepper motor moves a micro-flow control valve in response to any error between the desired flow and the actual flowrate as measured by this flow sensor. In addition, very precise flowrate settings may be set and maintained automatically over long periods of time. Provisions are available to change the flow rate from one setting to another remotely. Flowrate is uni-directional and is marked for proper direction on the serial number nameplate.