Computational Bias Magnetometer

You cannot correct what you cannot measure. The Computational Bias Magnetometer is the diagnostic instrument that transforms Hemispheric Inference Bias from an abstract specification into a visible, quantified reality in your computing environment.

The sensor is a 3-axis flux gate magnetometer — the same sensor technology used in spacecraft attitude determination, geophysical surveys, and submarine navigation. Flux gate sensors measure the DC and low-frequency magnetic field by driving a high-permeability core into saturation with an AC excitation signal and detecting the asymmetry in the saturation waveform. The asymmetry is proportional to the external DC field. Our implementation uses three orthogonal cores to measure all three components of the magnetic field vector simultaneously, at 100 samples per second.

The resolution of 0.01 nT is significant. The Earth's magnetic field at the equator is approximately 30,000 nT. The field from a power supply transformer at 300mm distance is approximately 50–200 nT. The field from a spinning hard drive at 100mm is approximately 5–20 nT. The Hemispheric Inference Bias specification of our Tropic GPU is < 8.2 nT — a figure that is measurable with this instrument but not with the magnetometer in your smartphone (which has a noise floor of approximately 100 nT). The distinction matters.

The EQ-BIAS software provides three views. The real-time view displays the magnetic field vector as a 3D arrow, with magnitude and direction updating at the full 100Hz sample rate. The trending view displays a rolling 24-hour graph of field magnitude, with annotations for inference benchmark events. The correlation view — the most revealing — plots inference throughput on the Y axis against magnetic field magnitude on the X axis, showing the statistical relationship between ambient field strength and computational performance. In our testing, this correlation is negative and statistically significant (p < 0.001) for every non-equatorial GPU we have measured.

The magnetic mounting clip is a spring-loaded clip with a ferrite base that attaches to any GPU backplate. This positions the sensor at the point of maximum relevance — directly adjacent to the silicon die where hemispheric bias has its computational effect. The clip is hinged to allow the OLED display to face upward through a case window or toward the user in an open-bench configuration.

CSV data export is provided for users who require magnetic environment auditing for warranty compliance or facility certification purposes. The logs include timestamped 3-axis readings at the full 100Hz rate, with metadata headers documenting the sensor serial number, calibration date, and firmware version. These logs are accepted as supporting documentation for Equatorial Audio warranty claims and Calibration Centre certification applications.