Summary
Grounding measurement turns an invisible condition into technical evidence. It is not only about obtaining an ohm value, but about understanding whether the system fulfills its safety, continuity and electrical reference function.
When to request a measurement
It is advisable to measure when an installation is commissioned, after modifications, during maintenance, before an audit or when there are doubts about electrical safety.
It is also recommended when there are damaged inspection chambers, modified conductors, load expansions, corrosion or incomplete records.
Common methods
The fall-of-potential method is a classic reference for measuring grounding resistance when there is enough space for auxiliary electrodes.
Ground clamps can be useful in systems with return paths, but they do not replace system analysis and do not apply to every case.
Common errors
Measuring without disconnecting or without understanding parallel paths can produce misleading values.
It is also common to confuse installed resistance with soil resistivity, omit physical inspection or fail to record humidity, configuration and measurement point conditions.
What the report should include
A grounding report should indicate method, equipment, date, conditions, location, results, photographs, observations and recommendations.
When the installation is critical, the report should relate results to safety, operational continuity, maintenance or commissioning.
Frequently asked questions
Does a low resistance value ensure that the installation is safe?
Not always. In medium and high voltage, step and touch voltages, fault current, clearing time and equipotential bonding also matter.
How often should it be measured?
It depends on criticality, environment, history and owner requirements; industrial installations usually require periodic control.
What is the difference between grounding measurement and resistivity?
Grounding measurement reviews an installed system; resistivity characterizes the soil for design.
Does IONIZE deliver a technical report?
Yes, the service can include a technical report, photographs, result sheets and recommendations.
If you need technical support applied to this topic, review our industrial grounding service.