How is compensation of an oscilloscope probe performed?

Oscilloscope probes have inherent capacitance that must be matched to the input capacitance of the oscilloscope to ensure accurate signal representation across all frequencies. This adjustment is known as probe compensation. To perform this compensation, a square wave is used because it is rich in odd-order harmonics. These high-frequency components make it immediately obvious if the frequency response is skewed. If the probe is undercompensated, the square wave's corners will appear rounded. If it is overcompensated, the corners will show sharp spikes or overshoot. Adjusting the probe's small variable capacitor until the top and bottom of the square wave are perfectly flat ensures the probe is correctly compensated.