Calibration
Every card carries its calibration
Each card that measures stores its own calibration record. Cards will ship calibrated against traceable standards, and you can recalibrate them against your own.
On the card
A memory chip on the card holds its calibration records. A record has the constants, the standards they came from (each standard's certified value, uncertainty, calibration date and certificate), and the temperature the card was calibrated at.
The record travels with the card, to another Base or to its next owner. The factory record is write-protected and kept, and later calibrations are stored beside it.
If no record checks out, the card reports itself uncalibrated. It never passes off a nominal value as a calibrated one.
Before it ships
Every card will be calibrated before it ships, against physical standards: for most cards a 10 V reference and a 10 kΩ resistor, each traceable to a national standard.
Traceable means each standard's own calibration is documented back to a national standard. It is not an accredited calibration, and we won't call it one.
Factory records are signed. The public key will be published, so anyone can check that a record came from Vec Labs.
Recalibrate it yourself
The factory procedure will be published, and it is the same one you run.
You need your own traceable standards, each with its calibration certificate. For most cards that's a 10 V reference and a 10 kΩ resistor, and each card's manual names exactly what it needs. An uncalibrated 10 V module is a number, not a standard.
Your calibration is stored on the card beside the factory one, and it's yours to sign or not.