The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 11, 1994
Filed:
Dec. 17, 1990
Kelly M Orth, Apple Valley, MN (US);
David W Lee, Farmington, MN (US);
Roger L Frick, Chanhassen, MN (US);
Rosemount Inc., Eden Prairie, MN (US);
Abstract
A transmitter for use in a process control system has externally accessible actuators for permitting external adjustment of the zero and span (or full scale) settings of the transmitter. The transmitter has an explosion-proof housing which includes an interior chamber in which transmitter circuitry is located. Each of the actuators includes a movable magnet which operates a magnetic reed switch located within the interior chamber of the housing through a wall of the housing. Each of the magnets is mounted on a movable actuator which extends into a blind hole in a wall of the housing. By moving the magnet within its hole, the corresponding reed switch can be changed from a non-actuated to an actuated state. When the zero reed switch is actuated, the transmitter circuitry adjusts its output so that the present value of the parameter represents a process zero. When the span (or full scale) reed switch is actuated, the transmitter circuitry adjusts its output so that the present value of the sensed parameter represents a process maximum.