Specifications

USN52 L Operating Manual Page 19
The dB REF key stores a selected reference echo signal for comparison against echoes from discontinuities.
Reference and incremental gain levels are also stored and displayed in the GAIN function box, as shown below.
Note that the incremental gain value replaces the word “GAIN”.
Reference GAIN is the instrument gain setting at the time that dB REF is enabled.
Incremental GAIN shows any change, relative to reference gain, since dB REF was enabled. A positive value
(+xx.x dB) indicates an increase in gain. A negative value (-xx.x dB) indicates a decrease.
Refer to Chapter 12 for detailed instructions on using dB REF.
The FREEZE key activates and deactivates the particular freeze mode selected via the FREEZE MODE function in
the lower menu level. If FREEZE ALL is selected, the entire A-scan display is frozen. FREEZE PEAK holds the
highest echo amplitude until deactivated. Chapter 7 provides details on all menu functions. The symbol appears
in the Status Line while Freeze is active.
Freeze is released on any key press or change in menu parameters,
except for the following: , , , , ,
, DATA SET, STORE, FILE NUMBER, LOCATION, FILE MODE, BAUD RATE, LENGTH, PARITY, COPY MODE, a-
THRESH, a-START, a-WIDTH.
4. Front Panel of the USN52 L