The Model 046, Blood Mimicking Fluid is intended for use in any flow phantom and with any type of pumping mechanism. It was formulated to simulate the acoustic and physical characteristics of blood, thus providing a stable and reliable fluid for Doppler studies and system evaluations. The fluid is non-hazardous and is formulated to meet the requirements for recommended blood-mimicking fluid as described in the IEC 1685 draft specifications. The fluid is fully degassed prior to packaging to minimize noise from air bubbles. In addition the scatters are neutrally buoyant thus preventing clumping and settling of the particles. Each batch of fluid is tested for speed of sound, attenuation, density and viscosity traceable to NIST.