There are 3 varieties of thermal mass flowmeters used in the industry. Immersible mass flowmeters, also known as a thermal dispersion or industrial thermal mass flowmeters include a number of instruments that measure the mass flow rate of fluids (primarily gases) that flow through closed conduits. Another type of thermal mass flowmeter is a capillary tube thermal mass flowmeter. Mass flow controllers, abbreviated MFC, combine electronics, a valve and a mass flowmeter. A thermal mass flowmeter is built measures the temperature differential across silicon-based MEMS chips.