Does calibration involve fixing electronics or mechanical part?
One way to use the calibration is to make no physical adjustments to the device. Simply do a mathematical adjustment to all the measurements you take with the device.

For example, an anemometer measures windspeed. Say you have a 5 mph reference flow and a 10 mph reference flow. Say in the calibration measurement, the 5 mph flow measures as 6.5 mph and the 10 mph flow measures as 12 mph. You then determine that the measured speed (I'll call it vm) is related to the real speed (v) by

\$v_m = 1.1v + 1\$

For your "live" measurements you'll reverse this formula to get the real speed in terms of the raw measurement:

\$v = (v_m - 1) / 1.1\$

So if you get a raw measurement of 8 mph, you use your calibration to estimate that the real speed was about 6.4 mph.

Of course the correction I described is based on a very simple, linear model of the instrument errors. In the real world, you might need a more complex model to get a correction formula that gives really accurate measurements.