ASTM D6820

ASTM D6820 is the ASTM standard guide for using the time domain electromagnetic method for geophysical subsurface site investigation. It provides a focused reference for applying this electrical geophysical technique in a site investigation setting, helping users better understand how the method is used to evaluate subsurface conditions. For engineering and environmental projects, this standard matters because it supports more consistent planning, execution, and interpretation of time domain electromagnetic surveys.

Purpose of ASTM D6820

The purpose of ASTM D6820 is to guide the use of the time domain electromagnetic method when investigating the subsurface. As a guide, it helps frame the method’s role in geophysical site work rather than setting a rigid test procedure. The standard is useful for aligning survey practice, equipment use, and interpretation with a recognized ASTM framework. That makes ASTM D6820 a practical technical document for teams that need a common reference for this investigation method.

Common use cases of ASTM D6820

This standard is commonly used in geophysical site investigation workflows where time domain electromagnetic measurements may help characterize subsurface conditions. It is relevant when planning surveys, selecting equipment, or comparing results from different locations within a project area. ASTM D6820 may also support project documentation and technical review when a recognized guide is needed for electromagnetic subsurface evaluation. Its use is typically tied to site assessment tasks that depend on nonintrusive geophysical methods.

Why ASTM D6820 matters

ASTM D6820 matters because it helps promote consistency in how the time domain electromagnetic method is used for site investigation. A shared ASTM reference can reduce ambiguity during procurement, field work, and reporting, especially when multiple parties are involved. It may also support quality control and risk reduction by helping users apply the method in a more controlled and comparable way. For organizations relying on geophysical data, that consistency can improve confidence in decisions based on subsurface interpretation.

• Guidance for time domain electromagnetic surveying
• Geophysical subsurface site investigation reference
• Supports planning and interpretation consistency
• Useful for technical review and documentation
• Applies to nonintrusive subsurface evaluation workflows