User's Manual

5 Using the manifold
16
Vacuum measurement
✓ The vacuum probe is plugged into the front connection of the
manifold and connected to the system.
1. Press
[Mode] the vacuum mode is displayed.
If ambient pressure is applied to the vacuum probe, then
oooo is
shown on the display.
2. Start the vacuum pump.
- Once the measuring range 0 to 20,000 microns is reached, the
current vacuum value is shown on the instrument display. The
instrument also displays the current ambient temperature, the
water evaporation temperature, which corresponds to the
vacuum reading, and the delta between these two
temperatures.
3. To leave vacuum mode, remove the vacuum probe from the
testo 557 or switch to the standard measurement view using the
[Mode] button.
Differential
pressure start
compared to
actual
Measured
pressure
beginning
of test
Duration
of test
Actual
measured
pressure