56
4 Design and Functions
p
1
V
1
= p
2
V
2
p = absolute pressure
V = gas volume
This is valid for the test of valve 1 V1:
Should t3 be negative, at least 1s must be set.
If the calculation of t3 for valve 2 is higher than t3 for valve 1, the value for the calculation of
valve 2 must be adjusted.
NOTICE
p
Schalt
must always be higher than p
out.
Otherwise V1 would be recognised as leaking even if it is not.
This is valid for the test of valve 2 V2:
If t3 is negative, at least 1 s must be set.
If the calculated t3 value of valve 1 is higher than t3 for valve 2, the calculated value of valve
1 must be adjusted.
Q
leak
Leakage rate in l/h
p
sw
Absolute pressure on the switching point of pressure monitor (adjusted over-
pressure + atmosphere pressure)
p
sw e
Adjusted overpressure on switching point of pressure monitor
p
out e
Output pressure on gas valve V2 during purge
p
Atm
Atmospheric pressure (average of 101,3 kPa at sea level)
V
test
Test volume between the valves
t2 Settling time is always 2 s
t3 Adjusted leakage check time
Q
leak
Leakage rate in l/h
p
sw
Absolute pressure on switching point of pressure monitor (adjusted overpres-
sure + atmosphere pressure)
p
sw e
Adjusted overpressure on the switching point of pressure monitor
p
in
Absolute input pressure on gas valve V1
p
in e
Overpressure at gas valve V1 input
p
Atm
Atmosphere pressure (average of 101,3 kPa at sea level)
V
test
Test volume between the valves
t2 Settling time is always 2 s
t3 Adjusted leakage check time
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