The paper examines two areas of continuity testing of lightning protection systems (LPS). Firstly the testing of the continuity of steel reinforcement used as down conductors of the LPS is considered. The paper shows that diagonal testing or the continuity, from say the top right back of the building to the bottom left front of the building, has some advantage over vertical testing where the test connections are vertically one above the other. Some theoretical multi-dimensional principles of this type of testing are formulated. Secondly continuity testing of the above-ground parts of an external LPS is considered. Consideration is given to testing with an applied voltage at various frequencies. This shows that there is an advantage when the frequency is al least 10 kHz and that conventional testing using a DC source is not of much value in an LPS with a meshed air termination.
