Other forms: calibrated, calibrating, calibrates
To calibrate is to set an instrument so its readings are true. Calibrate the scales, recently calibrated, calibrate against a standard.
It always means comparing against a known standard, and every standard is traceable up a chain to a national one — that chain is the whole point. An instrument that is precise but not calibrated gives you the same wrong answer every time.
1verbcalibrateTo set an instrument so its readings are true.
“The scales must be calibrated regularly so that they weigh accurately.”
calibrate is an adjusting.
From caliber + -ate.
Etymology from Wiktionary, CC BY-SA