The most significant disadvantage of pulsed-DC magnetic flowmeters is slower response time to
changing flow rates. In an effort to achieve a “best-of-both-worlds” result, some magnetic flowmeter
manufacturers produce dual-frequency flowmeters which energize their flowtube coils with two mixed
frequencies: one below 60 Hz and one above 60 Hz. The resulting voltage signal intercepted by the
electrodes is demodulated and interpreted as a flow rate.