®
7
Performance Test
©
F. Stephan GmbH
SA-103-0109V1.3-HAO-GB 25
7.4
Check of types of gas and test of the safety
devices
(Nitrous oxide blocking and O
2
-failure-alarm)
Apparatus in operating mode
Suction system for anaesthetic gas connected
Spindles of all proportioning valves opened to 3 l/min
Change-over-switch for AIR/N
2
O in N
2
O-position
7.4.1
Execution of the Test
Separate angular plug for O
2
from supply system
The flow of oxygen must decrease continuously
The O
2
-failure alarm sounds, when line pressure reaches approximately
2,8 bar
When pressure further decreases to approximately 2 bar, the nitrous-
oxide-blocking must set in and lower the N
2
O flow in parallel to the
oxygen flow, until, with the system completely emptied, both volume
flows have decreased to zero.
Oxygen supply is restored by inserting the angular O
2
-plug.
When the N
2
O-supply is interrupted, only the N
2
O-flow drops to zero
After restoring of the nitrous-oxide-supply, finally change over to AIR
and separate this gas from the supply pipe line. Here as well the flow of
N
2
O must drop to zero.
7.4.2 Proportioning
Valves
When the proportioning valves are closed, the respective floats of the
corresponding flowmeter tubes must move back to the zero position. If
this is not the case, a leakage of the respective spindle exists, which must
be eliminated by the service technician.
When carrying out this test, do not forget to change over from N
2
O to
AIR!