Gonio calibration is included in the calibration window. Press Calibration and select the channel with the Gonio. The Gonio calibration can be used to calibrate the gonio amplification and offset. Choose two angles, change the ginio to these angles and press Set lower / upper angle. If both angles are set, a button Set gonio appears. Pressing Set gonio calculates the amplitude and the offset for the selected channel so that the calibration to the physical unit (degrees) is possible. You can also use the classical approach. Measure the amplitude change when rotating the gonio for 30 degrees. Lets assume that the amplitude change is 1.5V. The correct entry for the physical unit of the channel is: 30/1.5 = 20 degrees per Volts. Enter the value 20Â° to the instrument. Afterwards, the offset needs to be adjusted. Rotate the gonio to 0Â° and change the offset to match 0V.