testo 54 Serie Bedienungsanleitung Seite 48

5 5 . . 6 6 M M a a i i n n s s H H u u m m F F i i l l t t e e r r
To reduce the interference from mains line and the environment (mains hum), the instru-
ment must be set to the local mains frequency.
Menu <–> Selection
press the
Page 22
local power line 60 Hz
local power line 50 Hz
keys to accept the selection