Another great treadmill calibration example can be found on fellrnr.com:

https://fellrnr.com/wiki/Treadmill_Calibration

The instruction is high quality and therefore worth to be published in a high quality journal such as Medicine & Science in Sports & Exercise, with DC Rainmaker as a first author with a group of really serious athletes who tests all treadmills he presented on his blog, and publishes a ranking which shows which is the most accurate treadmill.