Gradiometers are especially effective for discovering thoroughly decayed organic materials, such as those which accumulate in ditches and pits, and matter exposed to intensive firing, including industrial areas, hearths and larger ceramics.  All of these are likely to give a positive magnetic response, sometimes with a negative halo, giving a dipolar effect.  Non-igneous stone features, such as walls and banks, are usually perceived as negative anomalies against a background enhanced by decayed organics. 

Data is stored using a built-in logger, then transferred directly to a computer via Bartington’s Datalog programme. 

GeoFlo use Geoscan’s Geoplot 4.0, which supports statistical analysis and filtering of the data.  It allows the presentation of data in four graphical forms: dot-density, grey scale, pattern and X-Y (or trace) plots.  Typically gradiometer data includes high ferrous magnetic readings due to pipelines or metal debris which can be filtered out.  Thereafter small performance errors can be removed and mean values set to “0”, allowing a smooth data set.  Further enhancement may be achieved by a range of processes, most frequently including the interpolation of additional data points or the application of a gaussian low pass filter.