A Reevaluation of the Ultrasonic‐Vibration Method of Dispersing Soils

The ultrasonic vibration method of dispersing soils was reevaluated by studies with 28 soils that differed markedly in pH (3.6–8.2), carbonate content (0–34% CaCO 3 equivalent), texture (2–59% sand, 7–72% clay), and organic‐matter content (0.14–9.4% organic C) and included representatives of nine of the ten orders of the 7th Approximation. The results showed that ultrasonic vibration of soil‐water suspensions (2.5 ml of water/g of soil) by a high‐intensity probe‐type vibrator is an effective method for dispersion of, and yields stable suspensions with, a wide range of soils. They also confirmed previous evidence that tank‐type ultrasonic vibrators are not satisfactory for dispersion of soils and indicated that some reports of failure to achieve dispersion of soils by ultrasonic vibration can be attributed to use of inefficient vibrators.