The Bartington Grad601-2 is a single axis magnetic field graiometer sytem. It has two cyndrical gradiometrers with sensors seperated by a meter mounted on a carring bar. This instrument is designed for archaeological prospection and allows geophysical surveys to be completed rapidly. It also has applications for forensics and detecting the presence of instalations before excavation incliding pipes, cables and UXOs (unexploded ordinances).
For more info on the Grad601, please see the instrument web page at Bartington Instruments.