How Does A Thermal Dispersion Flow Meter Work?

Even though many technologies are available to measure the flow rate of air and gas, most of these methods measure the flow rate at the actual operating pressure and temperature, and they will require pressure and temperature correction before the mass flow can be calculated.

According to tradition, the most significant advantage of thermal dispersion flow measurement over volumetric gas flow measurement is the inherent ability to directly measure the mass flow without needing pressure and temperature correction as with volumetric gas flow measurement. Besides offering a more helpful flow measurement, thermal products are also very cost-effective due to their high efficiency. In addition, magnetron thermal mass flow dispersion meters allow users to conduct calibration verification in the field, a feature that is increasingly important to process industries.

Thermal Dispersion Flow Meter

According to the thermal dispersion principle of operation, the rate of heat transfer by a flow stream is proportional to the mass flow of that flow stream, which is one of the critical features of thermal dispersion technologies. By measuring the cooling effect as the heated sensor passes the mass (molecular) flow, it is possible to measure the flow rate of the mass (molecular) flow. It consists of two main components: the sensor and the signal processor.

1. The reference measures the temperature of the gas about the reference.
2. There is also a second element, which is heated by a variable electrical power to maintain the desired temperature difference between the two sensors at all times.

In the illustration below, we see the amount of power required to maintain a constant temperature difference between the two sensors simultaneously. Limited cooling is involved in operating a low-mass flow system, and the energy needed for the system is minimal. It is important to note that more power is required as the mass flow increases. With this feature, the flow sensitivity and turndown capability are low, resulting in excellent performance.

Ready to optimize your flow measurement process? Explore Burak Metering's Thermal Mass Flowmeter today for accurate and efficient mass flow measurement.