Patent 7559243 was granted and assigned to IRROMETER Company Inc. on July, 2009 by the United States Patent and Trademark Office.
An attachment for an instrument having a rotary shaft whose position is indicative of a value being measured. A needle is attached to the shaft with an inherent magnetic field, or which carries a magnet. A sensor responsive to the direction of the field is supported above the needle, and reads out the angle of the needle relative to the sensor. These readings can be used for monitoring and control purposes.