Durable detector locates large ferrous metal objects by being lowered into drilled boring holes.


Durable detector locates large ferrous metal objects by being lowered into drilled boring holes.

Specifically designed to find the presence of any ferrous metal in the ground at a radius of ± 8', you can rely on the Bore Hole Gradiometer (BHG) sensitivity and accuracy. 

The BHG system consists of 3 main items that are sold separately to facilitate its customization. The Control Box including a rechargeable 12v battery, a 50' sensor cable with Amphenol® connectors (custom lengths available) and a bull-nosed titanium sensor which works similarly to a magnetic locator and can also be used underwater. Its rugged and durable construction makes it ideal for utility companies, the construction industry, and bridge builders.

Technical Specifications


Electronics Panel Controls:
On, Off
Volume Up and Down
Range setting (Gain or Sensitivity) Up and Down
Zero, Plus and Minus
Auto Zero - Automatic self-adjusting

Audio Frequency Pitch (speaker and jack for headset)
Visual LCD Display
Bar Graph - range Gain setting - milligauss
RS-232 PC connection (cable included)
   control all keypad functions
   data log range, keypad and signal settings
   works with hyper terminal or equivalent

Power Options:
Internal Battery: 12 volt, 7.2Ah sealed lead acid
Battery Life: 72 hours continuous use, charges to full overnight
External Power: 12 to 15 volt, cable included
Internal battery charging circuit is enabled when external power or AC charging cable is connected

Operating Temperature Range:
-20° to 150° F (-29° to 66° C)
Electronics: 16.9" x 10" x 6.5"
Sensor: 1.625" x 17.5" (4.13cm x 44.45cm)

Key Features

  • Heavy-duty sensor cable acts as lanyard. 30’, 50’, 100’ (non-standard lengths available) 
  • High-quality connectors and “toilet seat” cover over headset jack. “Seacon” connectors available. 
  • Alligator clips for 12v auxiliary power. 
  • Gel-cell auto-charges when auxiliary power connected. 
  • “Zero" to “null” gradient. 
  • Permanent gel-cell battery-mounted under electronics panel. 
  • Bull-nosed and tapered Titanium sensor on BHG