Metal detector with microprocessor control and analysis
US4868910A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 16, 1988 |
| Grant date | Sep 19, 1989 |
| Priority date | — |
| Expiry date | Feb 16, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/107
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A metal detector for use in locating objects such as coins includes analog and digital circuits, further combined with a microprocessor and stored program routines, to provide enhanced ground exclusion balance, target discrimination, and ease of use. Both discrimination and ground exclusion balance are under microprocessor control. A ground exclusion balancing routine is automated and can automatically track any changes in ground mineralization, changing the ground balance setting whenever required. A plurality of memory registers, each corresponding to a different range of phase angles, can be coded by the user to indicate whether a target producing a signal in that phase angel range is a desirable object. When a target response is detected, its characteristic phase angle is calculated. The memory register corresponding to the calculated phase angle is then checked. If the register contains an ACCEPT code, the metal detector signals the user that an accepted target has been found. The program of the microprocessor allows the user to program the metal detector to accept or reject a particular type of metallic item by passing the search head loop assembly over a sample item a few ti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.