I just wanted to share with y'all a few tips that Dave Johnson sent me regarding my post about locating pipes at my friends place. Great tips and I hope everyone will benefit by them.....Here they are:
When you're tracing a pipe with a metal detector, the conventional way is to hold the coil horizontally and try to detect the metal in it. On the lower frequency metal detectors this is usually the only method that works.
With the (higher frequency) gold machines, esp. if it's a long pipe, you can often do better by holding the searchcoil in the vertical plane (gotta rotate the rod 90degrees) in line with the pipe. This method isn't nearly as efficient at detecting the metal in the pipe, but will induce currents along the pipe which the receiver will then detect like a pipe & cable tracer. Also works with buried cables since it's not the mass of metal you're trying to detect, it's the length. This method also has the advantage of reducing interference from trash in the ground.
With the T2 at a medium frequency, on a short pipe probably no advantage to this method, but on a run of 50-100 feet or more of metal pipe there's a good chance it'll work better. Next time you're tracing pipes or cables, I recommend giving this method a try. Appreciate it if you'll let me know how it works out.
Static pinpoint mode will probably work best since pipes & cables are deep targets with broad signals that don't kick in the motion circuits/software very efficiently. Push the button with the searchcoil aimed at least 45 degrees away from the line of the pipe/cable in order to reset the pinpoint to cancel drift.
Even if you're working in a red clay area, you may get better results by setting the ground cancellation to 90: this gives the greatest sensitivity to a linear induced signal.
--Dave J.
When you're tracing a pipe with a metal detector, the conventional way is to hold the coil horizontally and try to detect the metal in it. On the lower frequency metal detectors this is usually the only method that works.
With the (higher frequency) gold machines, esp. if it's a long pipe, you can often do better by holding the searchcoil in the vertical plane (gotta rotate the rod 90degrees) in line with the pipe. This method isn't nearly as efficient at detecting the metal in the pipe, but will induce currents along the pipe which the receiver will then detect like a pipe & cable tracer. Also works with buried cables since it's not the mass of metal you're trying to detect, it's the length. This method also has the advantage of reducing interference from trash in the ground.
With the T2 at a medium frequency, on a short pipe probably no advantage to this method, but on a run of 50-100 feet or more of metal pipe there's a good chance it'll work better. Next time you're tracing pipes or cables, I recommend giving this method a try. Appreciate it if you'll let me know how it works out.
Static pinpoint mode will probably work best since pipes & cables are deep targets with broad signals that don't kick in the motion circuits/software very efficiently. Push the button with the searchcoil aimed at least 45 degrees away from the line of the pipe/cable in order to reset the pinpoint to cancel drift.
Even if you're working in a red clay area, you may get better results by setting the ground cancellation to 90: this gives the greatest sensitivity to a linear induced signal.
--Dave J.