Data Sheet

7 First steps
12
7.2 Switching the instrument on and off
Current
status
Action Function
Instrument
off
Press
Instrument is switched on.
When the measuring instrument is started for the first time, the setup
wizard guides you through the following setting parameters step by
step:
- Language
- testo Smart App
Instrument
on
Press and hold
down (> 2 s)
Instrument is switched off.
The instrument setup that is implemented can be adapted at any time
in the Settings menu.
7.3 Setup wizard
When the testo 550s / testo 557s is started up for the first time and after the
factory settings have been reset, the setup wizard is activated and guides you
step-by-step through the following setup parameters.
The instrument setup that is implemented can be adapted at any time
in the Settings menu.
Language selection and QR code

Instrument is switched on and the initialization phase has been
completed.
1
Select language: Press [▲] / [▼]
and [Menu/Enter] to confirm.
Selecting the language activates
the appropriate presetting of the
units of measurement