Mindray DC-25, Service Manual

Page: 87 / 213

Function Checking and Testing 5-17
3. The measure caliper should be posited at the upper side or lower side
of the target center.
As shown in figure below.
5.5.2.4 Blackout Area
Test Step:
1. Cover the scan surface of the phantom with water or couple gel, gently contact the
probe with the scan surface
2. Adjust the depth at a lower value, and set the focus at the nearest place to the scan
surface.
3. Decrease the value of parameters like AP, Gain until the background noise just can
be seen.
4. Record the smallest depth of the target that can be seen clearly, that value is the
blackout area value.
NOTE:
1. When using a linear probe, please completely contact the probe with
the scan surface, no side clearance is allowed.
2.
For convex probe, the targets in the blackout area should be
positioned on the midline of the scanning plane.
As shown in figure below.