Geophones and their working principles

It has always been an aim of human scientists to try to predict the worst nature has to offer. To further this goal, we have pushed science on relentlessly to its limits and beyond, to come up with ways to understand the world around us. This has taken us on a journey through religion, education, and finally, science, where we truly are starting to understand the world we live in, through the lens of physics, biology and chemistry. Basically, these sciences are the stories of how we understand the world, and how we fit into it.

As our needs as a civilisation have grown, so have our aspirations. To this end, an entire industry has been set up around deciphering the chaotic patterns can appear to be. By and by, as man evolved he realised that weather and nature could in fact be predicted. Earlier, he used to tell by the pain in his arthritic knee, now he uses a hygrometer, but the result is the same, the prediction of rain. Our instruments have therefore evolved over the years, we can now predict with reasonable certainty many of the events that previously mystified us, and take action to safeguard ourselves. Storms, Tornadoes, even earthquakes can now be discovered hours in advance, giving us precious time to react appropriately.

In this article, we discuss one of these instruments, the geophone. The geophone is a device that can be embedded into the ground, or on many other things, to determine the intensity of vibrations in that surface. Obviously, this has many implications on the fields of seismography, but they have also found use in many other industries such as vibration monitoring and deep sea recording. So, what is the geophone? How does it work? Let’s see!

What is a geophone?

A geophone is a transducer, which is a device that converts variations in physical quantities to electrical signals. Specifically, the geophone converts ground motion in the form of shear or pressure waves into a voltage. The intensity of this voltage is the magnitude of the vibrations, and the change in the voltage can be recorded as the seismic response. The number after the geophone refers to it’s frequency, for e.g. a Geophone 8Hz has a frequency of 8 oscillations a second.

Who is this data useful for? What do they do with it?

This data is useful to geophysicists and seismologists, who use it

• To analyse the earths structure
• Determine the composition of the ground and its chemical makeup
• Predict and simulate the possible earthquakes and seismic activity that is likely to occur
• Discover and catalogue sites of seismic activity

A geophone is a ground motion transducer that has been used by geophysicists and seismologists to convert ground movement into voltage. Any deviation in this measured voltage from the base line is regarded as seismic response, which is used for analysing the earth’s structure.

How does it work?

A geophone is constructed in the form of a housing, that contains a mass that is suspended by springs. Upon vibration, the mass starts moving but the housing remains stationary, and the stress in the spring generates an electrical potential.

The geophone is a versatile device that is just starting to see the wide range of uses that it is capable of. As prices for the device fall with its increasing popularity, there are sure to be many new uses of this device that were previously not even thought of, so get your hands on one and be the first!