Before constructing bridges or high-rises, engineers need depth to competent layers. IX1D v350 identifies layers of high resistivity (dry sand/gravel) vs. low resistivity (clay, water-saturated silt). Version v350’s ability to output layer thicknesses with standard deviations directly informs geotechnical design.

Interpex Ltd. (Golden, Colorado) officially sunset active development of the v3.x series after 2015, focusing on their cross-platform IX1D v4 and IX2D v4. However, the v350 version remains widely circulated in academic and government circles. Why? Because it runs offline, requires no license server, and has a predictable, deterministic behavior—critical for regulatory work where reproducibility is key.

As of 2025, new users can still obtain v350 through legacy software archives or existing license transfers. For training, the original .PDF manual (circa 2002) remains the definitive guide, often bundled with geophysics textbooks.

For decades, geophysicists and hydrogeologists have relied on Vertical Electrical Sounding (VES) to map subsurface resistivity. The technique—rooted in the Schlumberger or Wenner arrays—produces raw data that is almost useless without robust inversion modeling. Enter Interpex, a name synonymous with reliable geophysical software, and their flagship product, IX1D.

The release of Interpex IX1D v350 represents a significant milestone. While earlier versions laid the groundwork for automated interpretation, v350 refines the user experience, updates inversion algorithms, and bridges the gap between field data and actionable geological models. If you still rely on legacy software or manual curve-matching, it is time to understand why IX1D v350 is the industry benchmark for 1D resistivity inversion.

Upon launching IX1D v350, you are greeted by a spreadsheet-style data editor. Columns typically include:

You can manually enter data or import from .RES, .DAT, or .SND files. The graphical editor plots the apparent resistivity curve (log-log scale). Anomalous points can be flagged and removed using the "Data Smoothing" tool, which applies a moving average filter.