### Abstract

Original language | English |
---|---|

Pages (from-to) | 034501-1 - 034501-8 |

Journal | Review of Scientific Instruments |

Volume | 76 |

Issue number | 3 |

DOIs | |

Publication status | Published - 2005 |

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*Review of Scientific Instruments*, vol. 76, no. 3, pp. 034501-1 - 034501-8. https://doi.org/10.1063/1.1867432

**Simple method for absolute calibration of geophones, seismometers, and other inertial vibration sensors.** / Van Kann, Frank; Winterflood, John.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Simple method for absolute calibration of geophones, seismometers, and other inertial vibration sensors

AU - Van Kann, Frank

AU - Winterflood, John

PY - 2005

Y1 - 2005

N2 - A simple but powerful method is presented for calibrating geophones, seismometers, and other inertial vibration sensors, including passive accelerometers. The method requires no cumbersome or expensive fixtures such as shaker platforms and can be performed using a standard instrument commonly available in the field. An absolute calibration is obtained using the reciprocity property of the device, based on the standard mathematical model for such inertial sensors. It requires only simple electrical measurement of the impedance of the sensor as a function of frequency to determine the parameters of the model and hence the sensitivity function. The method is particularly convenient if one of these parameters, namely the suspended mass is known. In this case, no additional mechanical apparatus is required and only a single set of impedance measurements yields the desired calibration function. Moreover, this measurement can be made with the device in situ. However, the novel and most powerful aspect of the method is its ability to accurately determine the effective suspended mass. For this, the impedance measurement is made with the device hanging from a simple spring or flexible cord (depending on the orientation of its sensitive axis). To complete the calibration, the device is weighed to determine its total mass. All the required calibration parameters, including the suspended mass, are then determined from a least-squares fit to the impedance as a function of frequency. A demonstration using both a 4.5 Hz geophone and a 1 Hz seismometer shows that the method can yield accurate absolute calibrations with an error of 0.1% or better, assuming no a priori knowledge of any parameters. (C) 2005 American Institute Physics.

AB - A simple but powerful method is presented for calibrating geophones, seismometers, and other inertial vibration sensors, including passive accelerometers. The method requires no cumbersome or expensive fixtures such as shaker platforms and can be performed using a standard instrument commonly available in the field. An absolute calibration is obtained using the reciprocity property of the device, based on the standard mathematical model for such inertial sensors. It requires only simple electrical measurement of the impedance of the sensor as a function of frequency to determine the parameters of the model and hence the sensitivity function. The method is particularly convenient if one of these parameters, namely the suspended mass is known. In this case, no additional mechanical apparatus is required and only a single set of impedance measurements yields the desired calibration function. Moreover, this measurement can be made with the device in situ. However, the novel and most powerful aspect of the method is its ability to accurately determine the effective suspended mass. For this, the impedance measurement is made with the device hanging from a simple spring or flexible cord (depending on the orientation of its sensitive axis). To complete the calibration, the device is weighed to determine its total mass. All the required calibration parameters, including the suspended mass, are then determined from a least-squares fit to the impedance as a function of frequency. A demonstration using both a 4.5 Hz geophone and a 1 Hz seismometer shows that the method can yield accurate absolute calibrations with an error of 0.1% or better, assuming no a priori knowledge of any parameters. (C) 2005 American Institute Physics.

U2 - 10.1063/1.1867432

DO - 10.1063/1.1867432

M3 - Article

VL - 76

SP - 034501-1 - 034501-8

JO - Review of Scientific Instruments

JF - Review of Scientific Instruments

SN - 0034-6748

IS - 3

ER -