What this comparison shows
Select one of the four electrode depths in the Fluke fall-of-potential brochure. The result reproduces that row's inner-probe and outer-electrode distances, calculates the separation between those two positions, and shows positions 1 m on either side of the brochure's probe location.
All displayed distances are measured from the tested electrode E along the source drawing's straight test line. The result is a comparison of manufacturer documents, not a recommendation to place stakes at those positions.
Source-table method
The four published rows are 2 m depth: S at 15 m and H at 25 m; 3 m: S at 20 m and H at 30 m; 6 m: S at 25 m and H at 40 m; 10 m: S at 30 m and H at 50 m. The S-to-H gap is H distance minus S distance. The check positions are S distance minus 1 m, S distance, and S distance plus 1 m.
The 1 m positions mirror the brochure's described probe-reposition check. The brochure's “significant change (30%)” wording does not define the percentage denominator, and this page does not calculate or apply that threshold.
Source conflict and limits
The Fluke 1625-2 manual's printed page 22 says the probe should be outside the potential-gradient regions and normally describes more than 20 m from E to each stake and more than 20 m between the stakes. The brochure's depth table gives specific distances that do not satisfy both of those general spacings. No precedence or reconciliation is established here. Confirm the applicable instrument instructions and test procedure before any field use.
The ±1 m check does not establish that the electrode/test-line geometry, soil conditions, parallel paths, instrument state or site distance are suitable. A browser calculation cannot decide that the resistance reading is stable or valid. The full grounding-electrode measurement method and any installation acceptance remain outside this page.
This page does not implement the separate four-stake soil-resistivity test, selective/clamp test, stakeless test, 62% shortcut or a resistance pass/fail limit. It gives no instruction to disconnect grounding or bonding conductors.
Common questions
Does this give me a valid stake layout?
No. It reproduces the brochure row and displays the conflict with the manual's general spacing guidance. No valid layout is determined.
Does the one-metre movement decide whether readings are stable?
No. It shows the two probe positions around the table position. The brochure's 30% wording is ambiguous, and the calculator does not interpret measured readings or uncertainty.
Does this calculate a ground resistance result?
No. It plans no measurement operation and calculates no resistance, soil resistivity, pass value or code decision.
Related tools
Sources and scope
Fluke, Earth Grounding Resistance: Principles, testing methods and applications, printed 2017, printed/p. 8, fall-of-potential method and depth table. Fluke 1625-2 Users Manual, January 2014, printed pp. 20–22, especially p. 22, spike placement and repositioning remarks. The documents' spacing statements conflict as displayed above; neither is converted into a pass/fail criterion.
These are manufacturer measurement references, not Canadian code approval. No resistance threshold, jurisdiction, product acceptance, safe-work procedure or qualified field review is asserted. Report a source issue; no test data is attached automatically.