Method of testing for response abnormalities in a magnetic sensor
AssigneeInternational Business Machines Corporation
InventorsPeter Cheng-I Fang, Christopher Dana Keener, Kenneth Donald Mackay, Frederick William Stukey, Jr.
Life of this patent
Estimating the term…
Abstract
A method is disclosed for determining the presence of response abnormalities in magnetic sensors. The method includes placing the sensor in an applied magnetic field and collecting sensor resistance information as the magnitude and direction of the applied field is altered. The resistance values are then examined to determine the presence of response abnormalities.
Claims7
A method of testing a magnetic sensor for the presence of a response abnormality of the sensor to an applied magnetic field, comprising:
- placing the sensor in the applied magnetic field;
- incrementally changing the value of the applied magnetic field;
- wherein at each value of the applied magnetic field a first measurement of the sensor output is made, then the direction of the field is reversed, and a second measurement of the sensor output is made;
- and,
- determining the presence of a response abnormality by examining the sensor output measurements.
A method of testing a magnetic sensor for the presence of a response abnormality of the sensor to an applied magnetic field, comprising:
- placing the sensor in the applied magnetic field;
- incrementally changing the value of the applied magnetic field;
- wherein at each value of the applied magnetic field a first measurement of the sensor output is made, then the direction of the field is reversed, and a second measurement of the sensor output is made;
- and,
- creating a transfer curve by plotting the value of the sensor output vs the value of the applied field;
- determining a slope of the transfer curve at each value of the applied magnetic field;
- and,
- determining if any value of the slope exceeds a predetermined value.
A method of testing for the presence of response abnormalities of a magnetic sensor to an applied magnetic field, comprising:
- placing the sensor in an applied magnetic field;
- incrementally changing the value of the applied magnetic field through a range of about zero to a preselected maximum value;
- measuring multiple values of resistance at each value of the applied magnetic field by repeatedly performing the sequence of,
- a) making a resistance measurement of the sensor,
- b) reversing the direction of the field,
- c) making another resistance measurement of the sensor, and
- d) reversing the field back to the first direction;
- and,
- determining the presence of abnormalities by examining the range of resistance values at each field value.
Dependencies are inferred from the claim text.