The working principle is different: the electromagnetic flowmeter uses the electromagnetic induction principle to measure the flow of conductive fluid by measuring the electromotive force generated when the conductive fluid passes through the external magnetic field; Vortex flowmeter obtains the flow value by measuring the frequency of vortex street.
Different measuring media: electromagnetic flowmeter can measure various conductive liquids, such as water, sewage, seawater, various acid-base solutions, various industrial liquids, etc. Vortex flowmeter can measure steam, compressed air, liquid and other gases, but it can't measure conductive liquid.
Different temperature requirements: electromagnetic flowmeter requires that the temperature of measuring medium should not be too high, generally below 50℃; Vortex flowmeter is not so strict with temperature, and high temperature gas or liquid can be measured easily.
Different structural forms: electromagnetic flowmeter has two structural forms: one is that the transducer and sensor are installed together, and the other is that the sensor and transducer are installed separately (with 5M cable).
I hope these data can help you understand the difference between electromagnetic flowmeter and vortex flowmeter.