An economizer controller with sensor calibration. A controller sensor may be used to measure a parameter. At the same time at the same location of the measurement with the controller sensor, a measurement of the same parameter may be made with a precision sensor. The difference between the two measurements may be saved to a controller memory as an offset. The offset may be used to compensate future measurements of the same parameter by the controller sensor. Additional offsets at various magnitudes may be obtained between the precision and the controller sensors for compensating subsequent measurements by the controller sensor. Measurements with the compensated sensor may be used for calibrating sensors in other economizer controllers, for example, at remote locations in the field.