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What is the principle of seismic instruments?
An instrument sensitive to tiny movements in the ground. A seismometer is a device that is sensitive to vibrations. It works on the principle of a pendulum: a heavy, inert mass with a certain resistance to movement (i.e. inertia) due to its weight is suspended from a frame by a spring that allows movement.
What is a seismic probe?
The seismic or velocity probe/transducer will measure total vibration at whatever point it is attached to – usually the bearing housing of a running machine. The proximity probe measures actual shaft movement, usually within its bearing housing, onto or through which it is usually mounted.
How do seismic sensors work?
In inertial mass type seismic sensor, the mass is kept stationary because of its inertia or by applying external means. Because of an earthquake, the support of the sensor vibrates producing a relative motion between the mass and the frame of the sensor. This relative motion is used to measure the earthquake magnitude.
What is seismograph explain its working with a neat diagram?
An instrument used for recording the vibrations caused by earthquakes is known as seismograph or seismometer. The vibrations are recorded on a strip of paper and the diagram produced is known as a seismogram. Numerous models of seismographs are in current use.
How does a seismometer work for earthquakes?
Seismographs are instruments used to record the motion of the ground during an earthquake. As the seismograph shakes under the mass, the recording device on the mass records the relative motion between itself and the rest of the instrument, thus recording the ground motion.
What are the three types of seismic waves?
There are three major kinds of seismic waves: P, S, and surface waves. P and S waves together are sometimes called body waves because they can travel through the body of the earth, and are not trapped near the surface. A P wave is a sound wave traveling through rock.
What is seismic activity and how is it measured?
The USGS currently reports earthquake magnitudes using the Moment Magnitude scale, though many other magnitudes are calculated for research and comparison purposes.
Why seismic codes are useful?
Seismic codes help to improve the behaviour of structures so that they may withstand the earthquake effects without significant loss of life and property. Countries around the world have procedures outlined in seismic codes to help design engineers in the planning, designing, detailing and constructing of structures.
What seismic waves tell us and how seismographs work?
Seismographs can detect quakes that are too small for humans to feel. During an earthquake, ground-shaking seismic waves radiate outward from the quake source, called the epicenter. Different types of seismic waves travel at different speeds and through different parts of the Earth during a quake.