Another disadvantage of the Geophone is its sensitivity, which can lead to problems in accuracy if it falls or is dropped. Such an impact can change the response of the Geophone. This fact is rarely detected in the field.
In addition to the (mostly unknown) measurement error of the sensor / Geophone, according to a study of different instruments, it has also detected a measuring range of about 25% where the accuracy is another 10%. (See collaborative study of the province of North Brabant http://www.abcgeluid.nl/trillingsmeter-sbr.)
The measurement inaccuracy is considerable. This spread, in combination with a variety of other systematic errors that occur, by definition, in the measurements and the above-mentioned problems in the use of Geophones, ensure that the probability of drawing a false conclusion (in the field) is high.
The AuroVibe has resolved these problems by using a modern tri-axial planarhear piezoelectric accelerometers with temperature monitoring. This sensor is completely sealed in stainless steel housing and protected against bumps, drops and throwing to 200 g (12.4 cubic foot). The high-quality ceramics of this sensor provides a pure, stable measurement for many years, with a completely flat frequency response in range without electronic corrections and annoying phase distortions.
Figure 1: Typical response of the acceleration sensor.
typical low frequency response, AuroVibe