Thursday, May 18, 2017

Thermal Flow Measurement for Gases

thermal mass flow meters for gases insertion and in-line
Installation variants of thermal flow meters
Thermal mass flow measurement technology has been used in industrial process measurement and control applications for many years. The basic operation involves measuring flow in relation to its heat dissipating effect on a temperature sensor. Higher mass flow produces a higher rate of heat transfer.

The mass flow measurement instruments are very popular for several reasons. They have no moving parts, have a fairly unobstructed flow path, are accurate over a wide range of flow rates, calculate mass flow rather than volume, measure flow in large or small piping systems, and do not need temperature or pressure compensation. While most thermal flow meters are used to measure flowing gas, some also measure flowing liquids.

Thermal mass flow meters are cost effective and accurate making it an excellent choice for a wide variety of gas flow applications.

The technology measures the amount of heat required to maintain a sensor at a reference temperature, offsetting the cooling effect of the mass flow over the sensor. The technology is well suited for installations requiring the measurement of low pressure gases where the fluid components are known and remain constant. Thermal mass flow measurement is also employed effectively in a number of other scenarios.

Potential advantages of thermal mass flow technology for industrial process measurement and control:
  • True mass flow reading using a single instrument
  • No significant impact on measurement from fluid pressure or temperature
  • Comparative cost is moderate
  • No moving parts
  • Minimal restriction of flow introduced by sensor
Thermal mass flow sensors have attributes making them very suitable for a family of applications. Like all measurement technologies, there are also areas of caution in their application. Any measurement technology must be properly applied in order to obtain reliable results. Talk to a sales engineer about your flow measurement ideas and applications. Combining your process expertise with the knowledge of a product application specialist will produce good results.