Agenda
- Physical Theory of Operation
- MEMS Magnetometers
- Fluxgate Magnetometers
- Pre-Calibration Accuracy Expectations
- Calibration Process Description
- Sample Calibration Results
- Where ISCWSA Can Add Value
MEMS Magnetometers
- Physical Theory of Operation
- Lorentz Force
- For a Current Carrying Wire
- Actual Measurement: Displacement
- Relative Capacitance
- LED
- Shift in Resonant Frequency
- Measurement Chain
- Relative Capacitance → Spring Displacement
- Spring Displacement & Spring Constant → Spring Force
- Spring Force & Current Magnitude → Mag. Field Strength
- Mag. Field Strength & Alignment → Mag. Field Vector Component
- Capacitance Measurement Concept Visualization
- Each green and red plate pair forms a capacitor
- Ideally, C1 & C2 are equal when displacement is zero
- A bias results when this is not true
- Errors in multiplicative terms form scale factor errors
- Spring constant
- Current measurement
- Misalignments have two sources:
- Sensor axis non-orthogonality
- Sensor triad alignment with chassis
- Each green and red plate pair forms a capacitor
Fluxgate Magnetometers
- Physical Theory of Operation
- Drive Winding: Biot-Savart Law
- Core: Ferrous Magnetic Domains
...
View the entire Presentation:
Chad Hanak (Speaker)