Free Air Delivery Measurement - Fad (Optional) - Siemens SITRANS FX330 Operating Instructions Manual

DEVICE DESCRIPTION
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2.2.7 Free air delivery measurement - FAD (optional)

To create compressed air, a compressor draws in air from the ambient atmosphere,
compresses it and delivers it at the required pressure. Since the ambient atmosphere also
contains water vapour, the compressor draws in a mixture of air and water vapour. In addition to
the moisture in the air, the ambient temperature and pressure conditions on the inlet side and
the process conditions on the outlet side also influence the compressor capacity.
That is why most manufacturers specify compressor capacity as free air delivery at standard
intake conditions. To compare the capacity of different compressors or to compare the capacity
of a compressor at different points in time, the measurement of the air supplied by the
compressor must be corrected by the influences of the process and of the environment and
converted to these standardised suction conditions.
The vortex flowmeter with optional FAD function (FAD - Free Air Delivery) can measure the free
air delivery online, regardless of its function as standard flowmeter. For this the device needs
the process and ambient conditions, as well as the compressor data. When installed on the
outlet side, it measures the air volume generated by the compressor and the process conditions.
The menu-driven, user-friendly software prompts the operator to enter the following values:
• Ambient temperature (inlet)
• Atmospheric pressure (inlet)
• Air humidity (inlet and outlet)
• Motor speed (rated speed and actual speed)
• Pressure loss of the air filter
The FAD value is calculated from the measured and entered parameters using the vapour and
compressibility tables stored in the measuring device.
INFORMATION!
• For correct FAD measurement the compressor must run at full capacity.
• FAD measurement is an optional feature, which can be unlocked subsequently in menu "C6.3
Extras" if not unlocked by order.
Please contact the manufacturer to obtain the four digit code required to enable this feature.
For programming example refer to Settings for free air delivery measurement - FAD on page
89 .
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SITRANS FX330
08/2022 - A5E36751269-AG EN