Using the CATT System
Possibly one of the best features of the CATT system is its ease
of use. Data collection and analysis is straight forward and very
little operator training is required. There are basically four steps
for performing a tap scan. The basic steps in producing a scan are
to 1) connect system components and configure the software, 2) attach
a grid template to the area to be inspected, 3) tap the area using
the manual tap probe or the semi-automated inspection cart, and 4)
analyze the data. These steps are briefly described below.
Step 1. Connect system components and open the CATT software.
The system consists of a computer interface box that connects to a
computer and a tap unit. Depending on the inspection application,
the manual tap probe or the semi-automated inspection cart may be
used. The manual tap probe is useful for performing spot checks and
for performing tap scans on curved surfaces. The inspection cart significantly
speeds the collection of data when inspecting relatively flat surfaces.

The CATT software is Windows-based. On the main window, the individual
tap duration values are displayed so that the system performance can
be checked and spot tests can be performed. Clicking on the "Set
Up A Scan" button brings up a window where the scan parameters
are entered.

Main Screen

Scan Set Up Screen
Step 2. Attach template to surface. Templates of nearly any
size may be used and grid spacing of 1/4, 1/2 and 3/4 inch are commonly
used. The smaller the grid spacing the higher the resolution of the
scan image.

Step 3. Tap the area using the manual tap probe or the semi-automated
cart. When the manual unit is used each square of the grid on the
template is hand tapped. When the inspection cart is used, it is pushed
along each of the grid lines and the cart taps at a regular interval.
The tap spacing can be set to 1/4, 1/2 or 3/4 inch. The tap duration
data is fed into a spreadsheet where it is displayed as shown below.
Visual and audio ques are provided to assist in the data collection.

Step 4. Analyze the data. When the area has been completely
tapped, the tap duration and stiffness plots are displayed. The analysis
program can then be launched for additional data analysis and display
options. For example, the tap duration can be displayed or the component
surface stiffness can be calculated and displayed in absolute or relative
terms. The C-scan images can be displayed as 2-dimensional or 3-dimensional
surface plots.

View
Video of
Test Panel Inspection Using the CATT System

(RM,
1MB)
(Note: the inspection shown uses a frame to further speed the inspection.
This frame is not normally used.)