Cirs Doppler String Phantom 043, User Manual, Page: 6 / 32

3
Using the Diffuser Mat
The black rubber Diffuser Mat is provided to reduce reverberations in the tank by absorbing and scattering the
ultrasound beam. Place the mat in the bottom of the tank with the ridges facing up, if desired.
Installing the String
If your Doppler String Phantom was shipped in a custom carrying case, the string target is already installed. If
not, you will need to install the string by doing the following:
1. Loosen the adjusting screw on the two pulleys at the end of the tank opposite
the motor.
2. Take one of the string loops out of the bag and lay it over the pulley that is
attached directly to the motor (Motor Pulley).
3. Draw the string half-way around the Motor Pulley, behind the two Idler Pulleys
below the motor, and around the pair of Adjustable Pulleys at the other end of
the tank. (See Figure 2).
4. Adjusting the string tension by moving the Adjustable Pulleys until the string is
fairly tight, but not tight enough to break. The actual tension will not affect the
data.
Figure 2: String Installation
About Reverberations:
Water conducts ultrasound
more efficiently than the
human body, so it may be
necessary to reduce the
power level on your ultra-
sound scanner to a mini-
mum for best results.
FILLING THE TANK
Place the tank on a firm surface and fill it with either cold tap water or velocity-corrected fluid (see sidebar).
Fill the tank until the two small pulleys beneath the motor are just submerged. This depth works well, but it may
be changed to meet your needs.
After filling the tank, there will be dissolved air bubbles in the water. For best results, wait an hour before using
the Doppler String Phantom so the water can de-gas.