Thermal mass flow measurement
Thermal Mass Flow Meters and Controllers make use of the heat conductivity of fluids (gases or liquids) to determine mass flow.
Coriolis mass flow measuring principle
A Mass Flow Meter operating on the "Coriolis principle" contains a vibrating tube in which a fluid flow causes changes in frequency, phase shift or amplitude, proportional to the mass flow.
Ultrasonic flow metering principle
The operation of Bronkhorst® ES-FLOW flow meters is based on the propagation of ultrasound waves inside a very small sensor tube.
The Bronkhorst® EL-PRESS pressure sensor is a piezo resistive bridge on the surface of a silicon chip.
Mass flow controller (MFC) theory
In the case of mass flow control, the output signal is continuously compared with a setpoint signal from a voltage source. Any deviations between setpoint signal and measured signal are translated into a solenoid control valve adjustment until the two signals are identical.
Theory and advantages of 'CEM' Vapor Control
The vapor generation system consists of a liquid flow controller, an MFC for carrier gas, a temperature Controlled-Evaporation-Mixing device (CEM) and a power supply / readout / control unit.
Volume Flow versus Mass Flow
The ranges of Bronkhorst's thermal mass flow meters / controllers for gases are specified in such units as ln/min, sccm or m3n/h. These units look like volumetric units, but in truth they are expressions of Mass Flow. What is the story behind this?