Patent · US Expired

Electronic level apparatus and method

US4932132A · kind A · utility

15Cited by
10References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 1, 1989
Grant dateJun 12, 1990
Priority date
Expiry dateMar 1, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01C9/06
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

This invention relates to an electronic level apparatus wherein a hollow torus is rotatably mounted in the level. A body of ferromagnetic fluid creates a horizontal reference and is sensed to provide an audible signal when a predetermined angular orientation is detected by the sensor.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.