Geophone

Overview

By a patented design Magnetic Innovations has succeeded in developing a geophone which significantly increases the bandwidth while maintaining very compact dimensions.

The geophone uses the principle of the moving magnet which eliminates the problems of the connecting wires and associated crosstalk. The large stroke of the sensor ensures that, for example by starting up a system, much margin for movement is possible so that ‘end of stroke’ problems with the sensor element will be avoided.

These characteristics make the Geophone ideal for active vibration suppression. This predominated in the tests of the development of a vibration isolation platform, in collaboration with MI-partners.

Features

The low natural frequency of the MI-VS003 vertical geophone enables a variety of possibilities where signals with low frequency need to be measured.

The long stroke allows the geophone to measure signals with a larger amplitude in comparison with short stroke geophones.

One of its main features is that by a patent pending technology the MI-VS003 is a fully passive geophone with a natural frequency around 1.4 Hz. Considering the small dimensions of the sensor this is a novelty in the geophone market today.

The passive functioning of the geophone in combination with its low natural frequency enables the use of so called stretching filters to further extend the measurement range well into the sub-Hertz range with an unsurpassed signal to noise ratio.

For applications requiring the measurement of low vibration levels the sensor is particularly suitable due to its excellent small signal behavior.

The robust design of the MI-VS003 is compatible with vacuum environments.

Specs

SPECIFICATIONS1

Frequency

Natural frequency, fn

1.4 Hz

Tolerance

±25%

 

Damping

Open-circuit damping (can be changed)

43%

Tolerance

±9%

 

Resistance

Standard coil resistance

4450 Ω

Tolerance

±5%

 

Sensitivity

Open-circuit sensitivity

63 Vs/m

Tolerance

±9%

Maximum magnet excursion p.p.

4 mm

 

Physical2

Diameter

68 mm

Height

87 mm

Weight

1070 g

Operating temperature

22 ˚C ± 10%

1.The specifications above are preliminary values. No rights can be derived from this specification.

2.For detailed dimensions please refer to the technical drawing, available upon request

Publications