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BCU 580 · Edition 11.15l
97
Parameters
10 .7 .4 Valve opening time 1 t
L1
Parameter 59
This parameter is used to define the opening time for
the valves (2 to 25 s) which are opened to fill or dis-
charge the test volume between the gas valves. If the
preset opening time t
L
= 2 s is inadequate (e.g. if slow
opening valves are used) to fill the test volume or re-
duce the pressure between the valves, bypass valves
can be used instead of the main valves.
The opening time may be longer than the 3 s permitted
by the standard (EN 1643:2000) if
– the gas volume which flows into the combustion
chamber is equal to, or less than, 0.083 % of the
maximum flow rate
and
– if bypass valves are used.