2.1
Conductivity factor: A measure
of the conductance between the nozzle's heat responsive element and
the fitting expressed in units of (m/s)0.5.
2.2
Rated working pressure: Maximum
service pressure at which a hydraulic device is intended to operate.
2.3
Response time index (RTI): A
measure of nozzle sensitivity expressed as RTI = tu0.5,
where t is the time constant of the heat responsive element
in units of seconds, and u is the gas velocity expressed
in metres per second. RTI can be used in combination with the conductivity
factor (C) to predict the response of a nozzle in fire environments
defined in terms of gas temperature and velocity versus time. RTI
has units of (m/s)0.5.
2.4
Standard orientation: In the
case of nozzles with symmetrical heat responsive elements supported
by frame arms, standard orientation is with the air flow perpendicular
to both the axis of the nozzle's inlet and the plane of the frame
arms. In the case of non-symmetrical heat responsive elements, standard
orientation is with the air flow perpendicular to both the inlet axis
and the plane of the frame arms which produces the shortest response
time.
2.5
Worst case orientation: The orientation
which produces the longest response time with the axis of the nozzle
inlet perpendicular to the air flow.