The Zener impedance is derived from the 1KHz AC voltage which results when an AC current having an RMS calue equal to 10% of the Zener
current(IZT or IZK) is superimposed on IZT or IZK. Zener impedance is measured at two points to insure a sharp knee on the
breakdown curve and to eliminate unstable units.
2)Valid provided that electrodes at a distance of 10mm from case are kept at ambient temperature
3)Measured under thermal equilibriun and DC test conditions.