A Variable representing physical measurements performed by a sensor, or calculations performed by a CASPart or the Main Control System to simulate a physical measurement.
Note 1 to entry: A physical quantity may be measured by an external sensor but is assigned to a specific CASPart.
Note 2 to entry: The measuring sensor may be integrated into the CASPart.
Note 3 to entry: A calculation performed on the Main Control System which is used by a Component shall be assigned to that Component.
EXAMPLE 1A temperature Quantity is measured by an internal sensor of a compressor at its outlet.
EXAMPLE 2A pressure Quantity is measured by an external sensor at the inlet and outlet of a filter.
EXAMPLE 3The isentropic efficiency of a compressor is a Quantity which is calculated by the Main Control System but assigned to the compressor.