The University of Southampton
University of Southampton Institutional Repository

Inter-laboratory calibration of low-field magnetic and anhysteretic susceptibility measurements

Sagnotti, L., Rochette, P., Jackson, M., Vadeboin, F., Dinares-Turell, J., Winkler, A., Larrasoana, J.C., O'Regan, M. and Roberts, A.P. (2003) Inter-laboratory calibration of low-field magnetic and anhysteretic susceptibility measurements Physics of the Earth and Planetary Interiors, 138, (1), pp. 25-38. (doi:10.1016/S0031-9201(03)00063-3).

Record type: Article


Inter-laboratory and absolute calibrations of rock magnetic parameters are fundamental for grounding a rock magnetic database and for semi-quantitative estimates about the magnetic mineral assemblage of a natural sample. Even a dimensionless ratio, such as anhysteretic susceptibility normalized by magnetic susceptibility (Ka/K) may be biased by improper calibration of one or both of the two instruments used to measure Ka and K. In addition, the intensity of the anhysteretic remanent magnetization (ARM) of a given sample depends on the experimental process by which the remanence is imparted. We report an inter-laboratory calibration of these two key parameters, using two sets of artificial reference samples: a paramagnetic rare earth salt, Gd2O3 and a commercial "pozzolanico" cement containing oxidized magnetite with grain size of less than 0.1 m according to hysteresis properties. Using Gd2O3 the 10 Kappabridges magnetic susceptibility meters (AGICO KLY-2 or KLY-3 models) tested prove to be cross-calibrated to within 1%. On the other hand, Kappabridges provide a low-field susceptibility value that is ca. 6% lower than the tabulated value for Gd2O3, while average high-field susceptibility values measured on a range of instruments are indistinguishable from the tabulated value. Therefore, we suggest that Kappabridge values should be multiplied by 1.06 to achieve absolute calibration. Bartington Instruments magnetic susceptibility meters with MS2B sensors produce values that are 2–13% lower than Kappabridge values, with a strong dependence on sample centering within the sensor. The Ka/K ratio of ca. 11, originally obtained on discrete cement samples with a 2G Enterprises superconducting rock magnetometer and a KLY-2, is consistent with reference parameters for magnetites of grain size <0.1 m. On the other hand, Ka values from a 2G Enterprises magnetometer and K values from a Bartington Instruments MS2C loop sensor for u-channel and discrete cement samples, will produce average Ka/K values that are unrealistically high if not properly corrected for the nominal volume detected by the sensors for these instruments. Inter-laboratory measurements of K and Ka for standard paleomagnetic plastic cubes filled with cement indicate remarkable differences in the intensity of the newly produced ARMs (with a standard deviation of ca. 21%), that are significantly larger than the differences observed from the calibration of the different magnetometers employed in each laboratory. Differences in the alternating field decay rate are likely the major source of these variations, but cannot account for all the observed variability. With such large variations in experimental conditions, classical interpretation of a "King plot" of Ka versus K would imply significant differences in the determination of grain size of magnetite particles on the same material.

Full text not available from this repository.

More information

Published date: 2003
Keywords: rock magnetism, magnetic susceptibility, anhysteretic remanent magnetization, calibration, instrumentation, relative paleointensity


Local EPrints ID: 11171
ISSN: 0031-9201
PURE UUID: bd200f87-cc4b-47e3-9a58-e3170ed77e8e

Catalogue record

Date deposited: 28 Oct 2004
Last modified: 17 Jul 2017 17:04

Export record



Author: L. Sagnotti
Author: P. Rochette
Author: M. Jackson
Author: F. Vadeboin
Author: J. Dinares-Turell
Author: A. Winkler
Author: J.C. Larrasoana
Author: M. O'Regan
Author: A.P. Roberts

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.