ArchaeoPhysica Ltd on the WWW

Geoscan Research FM36 Fluxgate Gradiometer

This instrument has for many years been the primary magnetic gradiometer in use in the UK for archaeological surveys. The two fluxgates, separated by 0.5m, are linked to provide a single difference (not gradient) value which is logged at regular intervals until some preset number of samples per line is walked. This entails walking at exactly the right pace to ensure the correct number of measurements are present in each line & at the correct spacing. The difficulties associated with doing this have led to many contractors adopting a 0.5m interval rather than more useful 0.25m.

It does have the advantage of being lightweight & easily transportable & the closeness of the fluxgates has proved invaluable for studies of iron-working sites.

Manufacturer

Geoscan Research, United Kingdom

Web site

http://www.geoscan-research.co.uk