Dakota Ultrasonics PX-7 DL User Manual

Page 14

Dakota Ultrasonics

When measuring, press against the top of the transducer with the

thumb or index finger to hold the transducer in place. Moderate pressure is

sufficient, as it is only necessary to keep the transducer stationary, and the

delay line seated flat against the surface of the material being measured.

Making Measurements

In order for the transducer to do its job, there must be no air gaps

between the wear-face and the surface of the material being measured.

This is accomplished with the use of a "coupling" fluid, commonly called

"couplant". This fluid serves to "couple", or transfer, the ultrasonic sound

waves from the transducer, into the material, and back again. Before

attempting to make a measurement, a small amount of couplant should be

applied to the surface of the material being measured. Typically, a single

droplet of couplant is sufficient.

After applying couplant, press the transducer (wearface down) firmly

against the area to be measured. The Stability Indicator should have six or

seven bars darkened, and a number should appear in the display. If the

PX-7 has been set to the correct sound velocity (see page 13), the number

in the display will indicate the actual thickness o f the material directly

beneath the transducer.