FCU Function Description
are both classified as measurement signals in accordance with particle size
and counted by an evaluation electronics system (4).
The measurement of the flow rate, which is necessary for specifying the
contamination class, is carried out by a built-in flow rate sensor (5), the
signals from which are also channeled to the electronic evaluation system
(4).
Ultimately, the evaluation electronics (4) calculate on a continuous basis the
particle counts and the NAS or ISO contamination classes for the reference
volume of 100 ml, based on the measurement signals from the optical sensor
and the flow rate sensor.
Here the measured values (up to 3000) are also stored on a continuous basis
as they arise, together with date and time, in a manner that is safe from
network outages. A battery-buffered real-time clock is available for this
purpose.
A flow control valve (7) is available for adjusting the pressure fluctuation-
independent flow of oil.
A hydraulic filter (8) with electrical contamination indicator is positioned
upstream from this for the purpose of protecting against failure due to
contamination.
The FCU can be operated via keyboard (12). Characteristic values for the
measurement can be modified and various kinds of presentation can be
selected in the LCD display (6).
If not set otherwise, the following information is continuously displayed during
the measurement (see also in this connection the chapter "The Display of the
FCU"):
•
the selected measuring mode
•
Progress of the ongoing measurement
•
Current value of the measurement results for 2 of the 4 particle size
channels
•
Tendency: increasing or decreasing
↓
•
Current flow value
•
only in the event of fault -> Error messages
Furthermore, the FCU also possesses 3 built-in relays with the following
functions:
Relays 1 and 2 are limit value switches (change-over contacts
)
and also
serve to control a filtration unit.
Relay 3 outputs the operational readiness signal (DEVICE READY)
(closing device; closed when FCU is ready for operation)
FCU 8111 /-Aviation
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BEWA FCU8111 3690427a en-us 2017-01-23.doc
2017-01-23
