Thursday, June 19, 2014

Low Flow Liquid Mass Measurement Using MEMS Technology Sensor

Size comparison of low mass flow sensor
A low flow sensor, patented by Integrated Sensing Systems Inc. (ISSYS), utilizing silicon MEMS technology provides low mass flow measurement in a package smaller than a dime.

MEMS stands for microelectromechanical systems and is a technology that, in general, is defined as miniaturized mechanical and electro-mechanical elements made using techniques of micro-fabrication.

The traditional components of a steel Coriolis flow meter, are now being fabricated by ISSYS using silicon processing technology. The result is a sensor that provides low mass flow measurement in a very small package. Because of silicon’s low weight and very high strength, it makes a perfect material to build a low-flow Coriolis mass flowmeter.

Principle of Operation:

The sensor is not dependent on the thermal properties of fluids, but rather measures mass flow directly. A very small volume, silicon sensing tube, vibrates at high frequency (greater than 20kHz), which nullifies any effects from external vibration. The mass flow of fluid causes a twist in the vibrating U shaped silicon tube, proportional to the mass flow. Accompanying the sensor is the MS-LVF meter with a variety of signal processing functions and outputs. The sensor also includes an embedded platinum RTD for temperature measurement. The combination of the RTD, the vibrating U tube and the math functions built in to the MS-LVF meter also allow for  temperature, viscosity, and density measurement.

The sensor, named the microCoriolus fluidic sensor, is perfect for low flow measurement in research, pilot plant and lab applications. Examples of applications where the ISSYS liquid flow meter can be used:
  • CVD thin film deposition using liquid precursors
  • Pilot plant low flow liquid metering
  • Laboratory flow measurements
  • Chemical dosing
  • Metrology
For more information contact Belilove Company-Engineers at (510) 274-1990.