Damping; Prf Mode (Pulse Repetition Frequency) - GE USM 36 Series Technical Reference And Operating Manual

5 Operation

DAMPING

This function is used for matching the probe. By setting
the damping of the probe oscillating circuit you can vary
the height, width, and resolution of the echo display.
The following settings are possible:
● 1000 Ohm
low damping, the echoes become higher and broad-
er.
● 50 Ohm
reduces the echo height but produces narrower
echoes with a higher resolution.
– Select the function DAMPING.
– Choose the required value.
5-16

PRF MODE (pulse repetition frequency)

The pulse repetition frequency indicates the number of
times an initial pulse is triggered per second. You can
decide whether you need the highest possible PRF val-
ue or whether you are satisfied with a low value. You
have three fixed steps and one user-variable step avail-
able for the adjustment.
The larger your test object, the smaller PRF values are
needed to avoid phantom echoes. However, the A-scan
update rate becomes lower in the case of smaller PRF
values; high values are therefore required if a test object
should be scanned fast.
The best way to determine the suitable PRF value is by
experimenting: Start from the highest step and reduce
the value until there are no more phantom echoes.
Issue 2 (12/2013)
Setting the pulser (function group PULSER)
USM 36