NDT Systems Nova 950 Series, Operating Manual

Page: 2 / 25

Nova Eclipse TG950 - Users Manual
7.3 Material M isidentification . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.4 Worn or M alfunctioning Probes . . . . . . . . . . . . . . . . . . . . . 38
7.5 Material Stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.6 Plated or Painted M aterials . . . . . . . . . . . . . . . . . . . . . . . . . 39
7.7 Abnormal or Unusual Thickness Readings . . . . . . . . . . . . 39
8. ACCESSORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
8.1 Standard Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
8.2 Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
9. PROBES AVAILABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
10. M AINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
WARRANTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
PRELIMINARY Rev 1.0
Nova Eclipse TG950 - Users Manual
1
1.0. INTRODUCTION
NDT Systems thanks you for your purchase of the NOVA TG950 Bench
Top Ultrasonic Thickness Gage, a precision instrument that provides
exceptional value and unmatched features. The TG950 provides ultra-high
resolution (0.0001 inch/0.001 mm) in a light-weight, Bench Top thickness
gage found only in larger, bulkier portables and bench-tops. A significant
advantage offered by the Nova 950 is the bright LED thickness display. This
display is very quick and easily viewable at a distance. The many additional
features contribute to the exceptional ease of operation and flexibility in
applications. The TG950’s rugged design assures dependable
performance for a wide variety of field and lab inspection requirements.
1.1 Principle of Operation
The NOVA TG950 enables measurement, display, evaluation, and
recording of corrosion and other conditions that can impair the safety and
function of countless structures, systems, and materials. Measurements
are made with access to only one accessible surface of the test object. A
large selection of high frequency single-element contact, delay-line, and
bubbler-type transducers can be used interchangeably to satisfy a multitude
of applications.
1.1.1 Basics of Ultrasonic Thickness Gaging
The NOVA operates on a principle similar to Sonar, but at much higher
frequencies (Megahertz range) and electronic speeds. An ultrasonic
frequency sound-beam is generated which emanates from the transducer
and is coupled into the test object.
High-frequency ultrasonic waves travel through monolithic materials at
essentially constant velocities, depending upon the type of material
supporting the ultrasonic wave. This fact provides the basis for accurately
measuring the thickness of metals and some non-metals, with access to
only one side of the test object.
The NOVA accurately senses the time interval between the initiation of a
short pulse of ultrasonic energy into the test object and the time taken to
travel through it. This time interval is short; for example, the velocity of
ultrasound in steel is approximately one-quarter inch (6.3 mm) in one
millionth of a second (one microsecond). Thus, in order for the NOVA to
accurately measure steel thicknesses from as small as 0.0050 inch to 20.00