Gradiomanometer (Gradio)


The gradiomanometer is a non-radioactive tool used to derive fluid density in a wellbore. It uses a high-resolution, differential transducer to measure the differential pressure over the length of a 24 in. column of fluid. The pressure enters the tool via two ports spaced 24 in. apart and a differential pressure measurement is taken. Since the column height and gravity are constants, the average fluid density is easily calculated. Due to the fast and sensitive response, this measurement can be obtained while continuously moving in the wellbore.

The tool is used to quantitatively establish the density of the fluid or gas in the wellbore and the depths of water/oil, water/gas, and oil/gas contacts are then derived from this information.

The gradiomanometer is used with other tools in a tool string, and transmits its data to either the telemetry tool or the memory adapter tool (MAT).


  • Derives Fluid Density in a Well

  • Measurements can be Obtained While the Tool is Moving or Stationary


The Gradio tool has a convenient field serviceable sensor that is quick and easy to access. The density readings produced by the Gradio tool are very accurate and highly sensitive.

Gradiomanometer (Gradio)