One of the most important factors to evaluate when selecting a soil moisture sensor is the volume of soil that is integrated into the volumetric water content measurement. For some applications, a sensor with a small volume of sensitivity is desirable (e.g. greenhouse applications, near‐surface measurements). However, in many field situations significant small scale heterogeneity is present in the soil, meaning that a small volume measurement may not accurately reflect the average volumetric water content at the measurement location. For most field applications a larger volume of sensitivity will minimize these issues and yield a more accurate measurement of the true volumetric water content. To this end, there has been considerable effort spent maximizing the volume of influence of the 10HS soil moisture sensor. This application note describes a set of tests that were conducted to quantify the volume of sensitivity of the 10HS, and the results of those tests.