Dakota Ultrasonics MVX - Manual (Page 31)

MVX High Performance Thickness Gauge
4.7 Glossary of terms
Repetition Rate & Display Update
The repetition rate is how often the MVX generates a burst of ultrasound.
The MVX has a fixed repetition rate of 1 kHz, or 1000 times per second. The MVX
updates the display 4 times per second in regular measurement mode and 32 times a
second in hi speed scan mode. Therefore, the scan mode is most suitable for fast
scans of a test piece at a lower resolution.
Variable Pulser Width
Transducers have a center frequency where they are most efficient at transmitting
sound (i.e. they are resonant). The MVX has a variable width pulser with three
setting options (spike, thin, wide). These settings determine the period of time the
pulser turned is on. High frequency applications, where resolution is a requirement,
may require the spike or thin settings to achieve optimal results. Low frequency
applications, where more penetration is a needed, may require the thin or wide
settings, offeri ng increased penetration. The variety of transducer frequencies and
diameters used in conjunction with the pulser settings, enable users to fine tune the
MVX for their application needs.
Gates
Gates control the time measurement process. They enable the user to select
measurement regions and threshold levels (sensitivity). The MVX is equipped with
two gates. In pulse-echo mode a single gate can be used to eliminate noise. In
echo-echo mode both gates are used. In this mode the second gate starts
automatically after a signal is detected during the gates region, and after a user
adjustable delay, sometimes called a hold -off.