The capacitor in the test circuit is charged by a high-voltage supply through a high-value resistor. The standard supply voltage is ±2 kV, the high-value resistance at 1 to 10 M, and the capacitance at 100 pF (with 10% tolerance). A high-voltage relay breaks the connection to the supply and creates a path for discharge to the DUT. The discharge resistance, representing the resistance from the metal contact to the DUT, is it 1.5 k? (with 1% tolerance).
These are just common values, though. In reality, the human body’s capacitance swings from 150 to 500 pF (affected by contact area and shoe size). Also, the discharge path should be characterized by a lower resistance given that metallic conductors are the more common medium. These inconsistencies are addressed by Standard IEC 802-2, recommending a capacitance of 150 pF and a discharge resistance of 330. However, this standard doesn’t directly involve integrated circuits.