For those in a hurry

No time to read the details? Here’s the short version:

• Why calibrate?
  Air slows down ahead of the bike, so Aerosensor’s dynamic pressure reading must be scaled up. This is called Aero Device Calibration in the CIQ app, or simply Aero Calibration or Cal in Aeroportal and Aeroworkbook.
• What affects calibration?
  Bike setup, rider position, sensor location – even helmet choice can make a small difference.
• How is it done?
  A calibration is calculated for every out-and-back run or lap of the velodrome, assuming zero average headwind.
• What affects calibration accuracy?
  Since we assume zero average headwind anything affecting the wind consistency will affect this.  Wind variability (shown as Hwind SD – headwind standard deviation in particular) will degrade accuracy.
• How accurate does it need to be?
  Keep the CIQ app calibration factor within 5% of the measured value:
  • For out-and-back tests, this is critical because it also affects altitude correction.
  • For velodrome tests, this is less critical.  Since altitude is not used (assumed to be constant) calibration can be corrected perfectly afterwards.
• How do I use it in post-processing?
  Both Aeroportal and Aeroworkbook offer Auto Cal, which applies the correct factor automatically. They also show:
  • 🟢 Green: repeatable calibration, stable wind → Auto Cal can be used confidently.
  • 🟠 Orange: some variability → check baseline repeatability; only use Auto Cal for smaller changes (<2%).
  • 🔴 Red: inconsistent data → Auto Cal not valid; only test changes that don’t affect calibration, with a constant calibration.
• Why does this matter?
  All aero devices require calibration, even if others hide it. Aerosensor gives you full visibility and control, so you can trust the results based on what you saw and tested. It’s a little extra work, but it leads to more reliable data.