Definition
A graph or chart that shows the relationship between the indicated values of an instrument and the actual (true) values, used to correct readings for known errors. The curve is created by comparing the instrument's output against a reference standard across its operating range.
Plain English
A chart that tells you how much an instrument's reading is off, so you can work out the real value from what the instrument shows.
Context Anchor
Seen in aircraft maintenance, instrument testing, flight-test data, and discussions of gauge or sensor accuracy.
Derivation
From Latin 'calibrare,' meaning to determine the size or accuracy of something. A 'curve' here just means the line on the graph that connects the correction values across the instrument's range — it isn't always curved, but the term stuck.
Why Pilots Care
Accurate instrument readings depend on knowing and applying these corrections so flight decisions are based on reliable data rather than hidden errors.
Analogy
It is like a correction chart for a bathroom scale: if the scale reads 160 pounds but the chart says the true weight is 158 pounds, the chart tells you how to interpret the reading.
Intuition Check
A calibration curve is not the act of adjusting the instrument. It is the chart or graph that shows how the instrument’s readings compare with known true values.
Example Sentence 1
The technician used the calibration curve to convert the indicated airspeed readings into true values during the post-maintenance check.
Example Sentence 2
During the pre-installation check the mechanic consulted the calibration curve for the temperature sensor to confirm it stayed within tolerance across the full range.