Nova Eclipse TG950 - Users Manual
16
options.
Note the scroll bars on the sides of the menu. This indicates there are more
setups available. Press the down arrow repeatedly to view other factory as
well as user defined (if any) transducer setups. In the AUTO mode, the
instrument will automatically recognize, select and optimize all necessary
parameters when using NDT Systems, Inc. NOVA Transducers. This
method is highly recommended for optimum performance and
measurement accuracy.
Direct Contact transducers (e.g., the C11) can also be used. The
Contact
option will yield a measurement range of
0.062
to
20.00" +
, with resolution
of 0.001 (0.01 mm) in the "NORMAL" mode.
The
Contact HR
(High Resolution) mode also permits certain high-
frequency direct contact transducers, such as the C11, to be used. W ithin
the specified range, the NOVA is automatically optimized to produce stable
measurements with resolution of 0.0001 inch (0.001 mm).
MODIFY Sub-Menu:
At
MODIFY
, ENTER, the following display opens:
Important Notice: It is within the M ODIFY Sub-M enu that many
internal adjustments can be made by the User to refine setups to
optimize the NOVA for special or difficult gaging applications.
For normal conditions, many of these adjustments are set
automatically, depending upon the transducer/measurement
mode combinations initially selected, and require no further
modification. Caution M UST be used when changing these
parameters to assure optimum accuracy. Further technical
discussion of these selections/adjustments follows in Section
5.3 of this M anual.
Nova Eclipse TG950 - Users Manual
17
Note:
The scroll bar on the left of the menu. This indicates there are more
items available below the 3 initially shown selections
Mode:
can be toggled between
Contact
and
Delay
with the Right and Left
Arrow keys. In the same manner,
Gates:
toggles between Auto, IP-1 , IF –
st
1 , 1 – 2 & 2 – 3 . These selection options refer to the measurement
st
st
nd
nd
rd
interval:
IF – First
is interface echo to first back-echo;
1 – 2
is first back-
st
nd
echo to second back-echo;
2 – 3
is second back-echo to third back-echo.
nd
rd
Auto
sets the measurement interval automatically, and, under normal
conditions, should be chosen.
Pulse:
toggles between
Normal
and
W ide
.
Normal
is the default condition. At
Pulse:
, continue pressing the Down
Arrow key to toggle down through an array of setup parameters that are
User-selectable and adjustable.
Also within the Main Menu, the
2 Point CAL
,
ALARMS
, and
THICKNESS
MODE
will be described in the Sections immediately following.
4.4 Calibration Procedures
W ith the Main Measurement display on, the NOVA TG950 is ready to be
calibrated for thickness measurement.
Single-Point Thickness Calibration:
Couple the probe to an accurately
known thickness on an appropriate reference standard within the expected
thickness range. If necessary, refer back to
Section 2.3
,
Reference
Standards
. Scroll with the Up or Down ARROW keys until the display
precisely reads the reference thickness.
Two-Point Thickness Calibration:
For
maximum accuracy over a range of expected
thicknesses, even under conditions where the test
object has smooth, parallel surfaces, two-point
calibration assures maximum accuracy. For some
applications, for example, smaller diameter tubing
or elbows, measurement accuracy also may be
improved with two-point calibration. However, it is necessary to have a
reference standard representative of the geometry to be measured. This
standard must have at least two accurately established thickness points.
(See
Section 2.3, Reference Standards
).
