The traditional method of measuring potential energy is to measure the angular deflection that the pendulum reaches after impact. The angle difference to the maximum deflection of the pendulum at an empty stroke (zero measurement) is a measure of the energy used to split the sample. The dynamic method (kinetic energy), on the other hand, measures the pendulum speed. The change in the pendulum speed is measured before and after the knock-off of the test angle and the energy used to split the sample is determined from the difference.