Electricity: measuring and testing – Of geophysical surface or subsurface in situ – For small object detection or location
Reexamination Certificate
2005-08-09
2005-08-09
LeDynh, Bot (Department: 2862)
Electricity: measuring and testing
Of geophysical surface or subsurface in situ
For small object detection or location
C324S330000
Reexamination Certificate
active
06927577
ABSTRACT:
A method of improving pulse inductive metal detector sensitivity by minimizing adverse ground responses and transmitter coil transients is disclosed. The method provides a calibration mode for a typical pulsed EMI metal detector. The purpose of the calibration mode is to determine and record a nulling signal representative of the transmitter coil coupling to the receiver coil and a ground response that has no metal. The nulling signal is then used during normal operation of the metal detector by combining it with the instant receiver coil signal in a difference amplifier. The difference amplifier effectively subtracts the nulling signal from the instant signal yielding a response signal that has removed the ground response that may be present in the instant signal. The metal detector can be periodically re-calibrated. It may also be re-calibrated upon discovery of a metal target to provide the most up to date nulling signal for the ground around the metal target.
REFERENCES:
patent: 4709213 (1987-11-01), Podhrasky
patent: 4868910 (1989-09-01), Maulding
patent: 5729143 (1998-03-01), Tavernetti et al.
patent: 6559645 (2003-05-01), Arndt et al.
patent: 6583625 (2003-06-01), Castle
patent: 2001/0010460 (2001-08-01), Miller et al.
patent: 2003/0034778 (2003-02-01), Nelson
Fasulo, II Albert J.
LeDynh Bot
The Johns Hopkins University
LandOfFree
Digital nulling pulse inductive metal detector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Digital nulling pulse inductive metal detector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digital nulling pulse inductive metal detector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3523851