1, the working principle is different: the seismograph uses the controlled pendulum or reed as the sensitive element, and measures the magnitude and frequency of the earthquake through the working mechanism, while the strong earthquake instrument uses the inertia force and magnetic field induction principle to measure the huge earthquake.
2. Different uses: Seismometers are mainly used to measure the magnitude of earthquakes, increase accuracy and provide data for earthquake research and prediction, while strong earthquakes are mainly used for earthquake disaster monitoring and earthquake early warning in emergencies.