Furthermore, a thermal mass flow meter can be built by measuring temperature differential across a silicon-based MEMS chip.
The principles of operation of the two types are both thermal in nature, but are so substantially different that two separate standards are required.
However, it was not until the 1960s and 1970s that industrial-grade thermal dispersion mass flow meters finally emerged.
The primary reason thermal mass flow meters are popular in industrial applications is the way they are designed and built.
In such applications, varying composition of the fluid during actual operation can affect the thermal flow measurement.