Specifications

5. Quick Start - Basic Familiarization

USN52 L Operating Manual Page 27

Press until the dB STEP value reads 1.0.

Use to set amplitude of the 1 inch backwall echo at 80% of

screen height (8 divisions high).

Now switch to the lower menu level by pressing

Find the GATE LOGIC function in the center column of menu 8

and frame that column of functions:

GATE LOGIC should be POSITIVE. If not, use

to set POSI-

TIVE logic.

Return to the upper menu level and A-scan:

or . Identify

the gate bar displayed in the A-scan.

Use

or to select the GATE menu.

Set gate threshold level (a-THRESH) to 50%, leading edge

(a-START) to 0.750 in, and width (a-WIDTH) to 0.500 in. Use

to make these adjustments.

Couple the probe again. The 1 inch backwall echo should be

roughly centered in the gate bar. Since the backwall echo ampli-

tude exceeds gate threshold, the alarm LEDs on the front panel

have been activated.

Select the MEASURE function (lower menu level) and set it to “0

to 1st”. Values now appear in the measurement line. S=x.xxx in,

soundpath distance to the first echo in the gate is not exact be-

cause the unit has not been precisely calibrated. Calibration pro-

cedures are provided in Chapters 9 through 12.

H=xx% is the amplitude of the highest echo in the gate. Increase

GAIN and observe the H value. The unit monitors amplitude up to

127% maximum. Decrease echo amplitude to about 80% again.

Press

. The gated portion of the A-scan fills the entire display.

Press again to restore the A-scan.

Press

. The soundpath distance has been highlighted in the

measurement line and enlarged in the upper right corner of the A-

scan display. Press

to scroll out of the measurement line and

disable the enlarged value display.

Now select the MEM menu:

or . You can STORE the current

instrument settings in a DATA SET and RECALL them at any time.

The unit has memory capacity to store 140 data sets. Because

the displayed A-scan image is stored with the data set, this feature

is useful for storing, previewing, and recalling flaw images, as well

as calibration setups.