The Bartington Grad601-2 is a vertical component dual sensor fluxgate gradiometer with data logger and two cylindrical sensor assemblies for use in geophysics and archaeology. Each sensor tube contains two fluxgate magnetometers with a one meter vertical separation. As a magnetic gradiometer, this instrument is sensitive to very slight fluctuations in the Earth's magnetic field as a result of object's buried in the shallow subsurface and surface variations. The on-board data logger records measurements collected during a survey and allows for gradient maps of a study area to be prepared.
This instrument is designed for archaeological prospection and allows geophysical surveys to be completed rapidly. The large non-volatile flash memory and fast downloading of data offer improved survey efficiency. The Grad601 has a linear range of 100nT with a resolution of 0.1nT and a range of 1000nT with a resolution of 1nT. A compressed response is provided to 30,000nT. This instrument operates either in survey mode, where data is recorded while covering an area in parallel or zigzag paths, or in a scanning mode where it is used as a search tool with an audible output without data logging.