The construction of a simple portable electromagnetic vibrator from commercially available components

Abstract

Since its introduction in the late 1950s, hydraulic vibrators have become the dominant source for land seismic surveys. The hydraulic vibrators typically used for commercial land seismic acquisition, however, are large, costly to operate and expensive to purchase. This inhibits their use for small‐scale and short‐duration surveys as well as Vibroseis research. In this paper we describe, in detail, the construction of a portable vibrator from commercially available components for a cost of less than $US2,000. Data shows that the vibrator is able to successfully transmit sweeps from 15 to 180 Hz with different spectral contents. The vibrator produces a stronger signal than a sledgehammer and we estimate its output to be around 1 kN. The frequency content of the data was concentrated at lower frequencies (<100 Hz) and the ground‐roll was far more energetic than that produced using a sledgehammer.

A 10 kN portable electromagnetic vibrator for near-surface studies

“…In our previous work (Dean et al, 2018), we showed how a simple electromagnetic Vibroseis source could be constructed from commercially available components. In this paper we created a new vibrator with the number of actuators increased from four to ten.…”

“…As with our previous unit the new vibrator was constructed from commercially available components (Table 1) but differed is several ways. Originally, we used the output from the computer's built-in sound card to play the sweeps but we found that the output from sound cards varied (Figure 5 in Dean, Nguyen, Kepic and Halliday (2018)) thus the output force of the vibrator would vary depending on the computer it was connected to. To overcome this issue we decided to test some external sound cards.…”

“…In a previous paper (Dean et al, 2018), we described how a small electromagnetic vibrator could be manufactured using commercially available components for less than US$2,000. The basis of the unit was a set of four low-frequency actuators designed for use in home-theatre systems.…”

Ground force analysis of a portable electromagnetic seismic vibrator for different surface environments and driving voltages

“…For example, Haines (2006) constructed a portable electromagnetic seismic vibrator using off-the-shelf audio components. Dean et al (2019) constructed an electromagnetic seismic vibrator using commercially available actuators. The other approach is to independently design the core vibration unit.…”

The Do-It-Yourself geophysicist

“…The cost of the components to make such a device is less than $200, including a small GPS receiver to provide 1us timing synchronisation with other sensors. Many geophysical measurements require changes to electric or magnetic fields, or use electrically controlled seismic sources (Dean et al, 2018A) and we may use modern developments in power electronics to our advantage. Solar, wind, and electric vehicles are creating a flood of new efficient electric power switching devices, with many evaluation systems providing ready-made devices for incorporation in to ideas.…”