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Vector Coil Calibration

Vector Coil Calibration (For Sensors with Vector Add-On)

Ensure your Gen-2 QTFM sensor’s firmware is updated to version 1_36, released on October 4th, 2024, to support vector coil calibration. If the firmware is outdated, follow the firmware update guide to upgrade before proceeding.

Steps for Vector Coil Calibration:

  1. Prepare the Sensor:
    • Navigate to the ‘Terminal’ tab in the user interface.
    • Let the sensor complete autostart and confirm the cell locks. For best calibration results, allow the sensor to run for about 5 minutes before proceeding.
  2. Verify Sensor Mode and Data Output:
    • Ensure the sensor is in vector mode and check that the X, Y, and Z data outputs are valid. This step is crucial to ensure the accuracy of the calibration.
  3. Initiate and Monitor Calibration:
    • Use the ‘Send Decimal’ button to send decimal command ‘6’ to the sensor. You should see a message: “#Calibrating Coil, keep sensor still.” Calibration typically takes 1-2 minutes.
    • Once calibration is complete, a status update will display the delta values for each coil, such as “#Delta_X:12040, Delta_Y:6900, Delta_Z:5954”.
  4. Lock Calibration Values:
    • To permanently store the new calibration values, use the ‘Send Decimal’ button to send command ‘9’. This final step updates the internal memory with the newly calibrated vector coil values.

Conclusion: Benefits of Vector Coil Calibration

Following the streamlined steps outlined above, your Gen-2 QTFM sensor will be accurately calibrated for the vector coils. Calibration enables the use of the new Enhanced Vector Mode, introduced in firmware version V1_36 and later. This mode is the default setting when vector mode is enabled (#Vector_Mode: 0), and outputs vector data similarly to previous versions.

Advantages of Enhanced Vector Mode:

  • Increased Tolerance to High-Frequency Noise: The Enhanced Vector Mode significantly improves the sensor’s ability to handle high-frequency noise, effectively increasing the bandwidth of each vector axis.
  • Optimized for Magnetic Surveys: This mode is recommended for conducting magnetic surveys due to its enhanced sensitivity and noise tolerance.

Consideration:

  • Initial Drift in Cold Start: One drawback of the new vector mode is that the sensor may experience drift for about 5 minutes when cold-started.

Hardware Update and Optional Modifications for Improving Vector Performance

New Vector Electronics Hardware:

  • Increased Sensitivity and Drift Reduction: Soon, new vector electronics hardware will be commercially available, further enhancing the vector sensor’s sensitivity and eliminating low-frequency drift.

DIY Modification for Enhanced Performance:

  • ECU Board Modification: In the interim, the top ECU board (vector electronics) can be modified to boost sensitivity and high-frequency tolerance.
  • Resistor Replacement: Replace the 0603 resistors on the top ECU board with resistors in the range of 150-220 ohms. See the Picture below for the resistor location.
  • Post-Modification Calibration: After this modification, it is crucial to recalibrate the vector coils to ensure optimal performance.