The µ-FLOW Series digital liquid flow meters and controllers for low flow ranges operate on a thermal, through-flow measuring principle. The instruments are equipped with a digital pc-board, featuring self-diagnostics, alarm and counter functions, digital communication (RS232), and a variety of Fieldbus options.
Measurement and Control of Ultra Low Flow Rates
μ-FLOW series are equipped with a digital pc-board, offering high accuracy, excellent temperature stability and fast response. The main digital pc-board contains all of the general functions needed for measurement and control. In addition to the standard RS232 output the instruments also offer analog I/O. As an option, an on-board interface can be mounted to provide CANopen, DeviceNet, EtherCAT, PROFIBUS DP, PROFINET, Modbus RTU, ASCII or TCP/IP, EtherNet/IP, POWERLINK or FLOW-BUS protocols.
Liquid mass flow meters of the µ-FLOW Series are built around a stainless steel tube without any moving parts or obstructions. The heater/sensor assembly is arranged around the tube and a constant power is applied to warm up the liquid inside the tube. Flowing liquid results in shift of the temperature difference (ΔT) which is proportional to the mass flow. Due to the benefits of the applied sensor, the fluid will be warmed to a maximum of 5°C, thereby making the µ-FLOW Series suitable for fluids with low boiling points.
Flow control is achieved by integrating a control valve onto the body of the Liquid Flow Meter. This control valve has a purge connection to eliminate air or gas during start-up. The electronic control function forms part of the normal circuitry in the meter.