User Manual

7 Maintaining the product
20
> Check instrument regularly for leaks (recommended: annually).
Keep to the permissible pressure range!
> Calibrate instrument regularly (recommended: annually).
Changing batteries/rechargeable batteries
✓ Instrument is switched off.
1. Fold out the suspension device, loosen the clip and remove the
cover of the battery compartment.
2. Remove empty batteries/rechargeable batteries and insert new
batteries/rechargeable batteries (4x 1.5 V, type AA, Mignon,
LR6) in the battery compartment. Observe the polarity!
3. Set on and close cover of the battery compartment (clip must
engage).
4. Switch the instrument on.
Cleaning the vacuum probe
Contaminants such as oil may impair the accuracy of the
vacuum sensor.
CAUTION
Carrying out cleaning with the probe connected may result in
damage to the probe!
> Remove the vacuum probe from the testo 557!
CAUTION
Damage to the sensor due to sharp objects!
> Do not insert any sharp objects into the probe!
1. Remove the vacuum probe from the testo 557.
2. Put a few drops of rubbing alcohol into the sensor opening.