Why should I use two different gun heads depending on the installed CR networks for ISO 10605 ESD testing?NoiseKen
he ISO 10605 standard specifies two different tolerances for peak current amplitude for four RC networks, as follows: +/-10% for 150 pF/330 ohm and for 330 pF/330 ohm and +30/-0% for 150 pF/2K ohm and for 330 pF/2K ohm.
The 2K ohm type gun head has a lower inductance component than the 330 ohm type to obtain a higher first peak current value. Note that a peaking effect (higher peak amplitude) for 150 pF/2K ohm and for 330 pF/2K ohm networks is done by the discharge circuitry but not by charge voltage adjustment. This approach is more faithful to the intention of the standard.