Soil Resistivity Field Logger

Report header & site

Company

Engineer / PE

Project no.

Client

Description (Desc.)

Station

Location

Project / Site

Operator (Tested by)

Date / time

Test equipment

Surface soil conditions / field notes

Traverses on map

Active

Active · Point A

— , —

Active · Point B

— , —

Bearing A→B

—

—m — active traverse length (used for spacing)

Adjust length — tape-measured (m) · overrides GPS; blank = use GPS

Add a traverse for each sounding line. Tap or GPS sets A/B on the active traverse; tap a line on the map to make it active. Every traverse is drawn with its length; all of them go into the Word report's location plan.

Base map & offline tiles

Tile URL template (must be CORS-enabled for offline)

Zoom levels to include

Tiles in current view

—tiles

Offline storage used

—

Service worker

—

Pan and zoom to your site while you still have signal, choose how many zoom levels deep to cache, then download. Tiles and the app shell are stored on-device so the map renders — and the report's map image composes — with no connection. The Word report reuses these cached tiles, so download your area before you lose signal. Requires HTTPS or localhost.

Recommended probe spacing (active traverse)

Min spacing a (m)

Step ratio

Max spacing aₘₐₓ

—m

Basis

aₘₐₓ = L / 3

Approx. investigation depth

—

Wenner electrodes sit at 0, a, 2a, 3a — so the outer current pins span 3a. The A–B line is taken as the widest reading (C1–C2 at aₘₐₓ); smaller spacings nest symmetrically about the A–B midpoint. Depth of investigation ≈ a (median depth ≈ 0.5a per Edwards). Min spacing and step ratio are shared across traverses; aₘₐₓ follows each traverse's own length.

Ambient conditions (site)

Fetched once for the whole site (centroid of all traverse points). Soil resistivity tracks moisture and temperature; recent rain lowers readings, dry or frozen ground raises them. Weather is a live call and won't refresh offline — fetch it before you lose signal.

Measurements — apparent resistivity

Input mode

Save / export

For CDEGS RESAP (active traverse, ascending a vs ρₐ)

Saved surveys (this device)

Field aid only — always confirm spacing series, array footprint, and interpretation against IEEE Std 81 and the requirements of your grounding study (e.g. CDEGS RESAP soil model). Apparent resistivity assumes a homogeneous half-space at each spacing; layered structure is resolved during model fitting, not in the field. Data is stored locally in this browser. Weather via open-meteo.com (no key). Base map © OpenStreetMap contributors.