Preventing False Minimum/Maximum Thickness Readings; Using Alarms - Olympus 38DL PLUS User Manual

The minimum and maximum thickness modes respectively display the smallest and
largest thickness measured value from the time you activate the minimum mode or
from the time you reset it. The modes are useful when it is important to determine the
thinnest/thickest reading obtained while making a series of readings on a test piece.
To activate the minimum, maximum, or min/max mode
1. From the measurement screen, press [SETUP MENU].
2. In the menu, select MEAS.
3. In the MEAS screen, set MIN/MAX to the desired mode (OFF, MIN, MAX, or
BOTH).
4. Press [MEAS] to return to the measurement screen.
5. In the measurement screen, press [MEAS] again to reset the held minimum,
maximum, or min/max values.
The thickness display will blank indicating that the old MIN/MAX value is reset.
Saving or sending a MIN/MAX reading also resets the value.
8.3

Preventing False Minimum/Maximum Thickness Readings

A false minimum or maximum reading can occur when you lift the transducer from
the test piece. This is due to excess couplant, particularly on smooth surfaces, which
causes the instrument to read the thickness of a couplant drop when you lift the
transducer.
To prevent false minimum/maximum thickness readings
1. Activate the minimum or maximum thickness mode (see "Using the Minimum,
Maximum, or Min/Max Thickness Mode" on page 115).
2. Before uncoupling the transducer, press [FREEZE] to freeze the waveform.
3. Once the transducer is uncoupled, press [FREEZE] again to unfreeze the display
and recall the minimum thickness and waveform.
8.4

Using Alarms

You can activate one of the 38DL PLUS alarm modes to help you identify when the
actual thickness measurement is above or below editable reference values.
When an alarm condition occurs, the 38DL PLUS warns you as follows:
DMTA-10004-01EN, Rev. D, November 2016
Using Special Functions 117