3. Setting Up the DMS 2
DMS 2 Operating Manual
Page 69
Calibrating to a Known Velocity
If you know the precise velocity of sound in the material to be
measured, the DMS 2 can be calibrated to the known
velocity without the use of a calibration standard. However,
the calibration should always be verified by measuring a
known thickness (or calibration standard) of the same
material and velocity as the material to be measured (Table
3-1).
3.3.5
Locking the Instrument Settings
Note that the DMS 2 is designed to automatically configure
the A-scan display based on information collected during the
calibration and probe-zeroing processes. (Refer to Sections
3.3.3 and 3.3.4.) Most users will find that the A-scan display
won’t need to be adjusted in most applications. In fact, it’s
typical that the operator will lock the instrument following
initial calibration and A-scan adjustment. This prevents the
operator from changing the A-scan, gate, probe setting,
calibration, zeroing, and other settings. While locked, the
instrument’s data recorder and measurement capabilities are
fully functional.
The instrument can be locked from the TEST or TG Mode by
pressing (at the same time) both the up and down arrows on
or
. At this time, the
will appear at the top of
the display screen.
The instrument is unlocked only from the TEST or TG Mode
by pressing (at the same time) both the up and down arrows
on
or
. At this time, the
will no longer be
visible.