Ethylene glycol-water mixture for use in ultrasound test objects

Ethylene glycol-water mixtures have been found suitable for use in ultrasound test objects. A plot of the required percentage of ethylene glycol with room temperature for an acoustic velocity of 1540 m/sec is presented to aid the clinical user. The velocity measurements performed are shown to be dominated by near-field transient diffraction effects. A 30 percent ethylene glycol-water mixture has been found to have a constant acoustic velocity of 1638 +/- 3.5 m/sec over a wide temperature range (15.6 degrees C-38.4 degrees C). This mixture is suitable for a test object velocity standard. Proper use of the A.I.U.M. 100-mm test object is discussed.