Method of the measurement of interstitial atoms in alloys including the hydrogen content of solid hydrides, and of sorbed species on surface

A method of detecting the concentration and depth of incorporated mobile atoms into a host material from a surface of the host material, wherein the host material is surrounded by a conducting electrolyte fluid, and the incorporated mobile atoms have diffused through and electronically interacted with said host material, which comprises:

• (a) propagating a variable frequency, periodic, electromagnetic signal along an axis of the host material;
• (b) calculating the depth of penetration of the signal at a fixed frequency, according to the following formula:
• Depth of Penetration=(2/(frequency of electromagnetic signal)(conductivity of host material)(electronic permeability of host material)).sup.0.5 ;
• (c) stepping the frequency of the electromagnetic signal to change the depth of penetration of the signal;
• (d) detecting impedence components of the electromagnetic signal at it enters and leaves the host materials;
• and,
• (e) calculating the volume fraction of incorporated mobile atoms at a specific depth based on the impedence data for each frequency as a function of the penetration depth of the signal at each frequency.