17
WIKA Operating Instructions - Ultrasonic Flowmeter FLC-UFL
81500908.01 08/2020 EN
EN
controlled. Gain values should be in the normal operating
range for all transducers.
Gain values depend on gas pressure, composition and
velocity, therefore, gain values may differ between events.
Gain
Condition
>70
Very weak or no signal
10 - 70
Good
< 10
Very strong or saturated signal
8.1.5 Signal to noise ratio (SNR AB and SNR BA)
The SNR is calculated in dB for each received signal
transducer. SNR values depend on gas pressure,
composition and velocity.
The below table provide information on Signal to noise ratio
conditions.
SNR
Condition
>50
Very good
25 - 50
Good
10 - 25
Poor – fair
<10
Bad
8. Maintenance / 9. Sealing, Shipping & Storage
8.1.6 Velocity of gas ratio (VOG ratio) and profile factors
The velocity of gas ratio is calculated between paths and
provides a good indicator of the flow profile in the meter
(determined by upstream piping). Profile factors are
calculated from the velocity of gas ratios. Profile factors are
an easy way to “understand” the flow profile in the flowmeter.
8.1.7 Velocity of sound ratio (VOS ratio)
The velocity of sound ratio is a good indicator of problems,
either in the process or in the FLC-UFL series signal
detection. During normal condition the ratios should be very
close to 1.0.
8.1.8 Path Status (PathStatus AB and PathStatus BA)
The Path Status diagnostic values provide a more detailed
indication of the health of each path in each direction
of transmission using an 8 digit number. A zero value
(0x00000000) indicates that all parameters are within limits
and no errors are present.
The error codes are tabulated in Appendix A.
9. Sealing, Shipping & Storage
9.1 Sealing
For sealing locations refer to document [2] FLC-UFL Series
Flowmeter Sealing Locations.
9.2 Shipping & Storage
Use suitable means for transportation, loading and unloading
of the packed FLC-UFL Series flowmeter. The packing is not
suitable for the use of strap belts and lifting by a crane.
If the flowmeter has been removed from its packaging, lifting
and moving may only be carried out using suitable, properly
fitted lifting lugs.
Take care that the meter will be installed on a vibration
free location. Continuous vibration or shocks may have an
adverse effect on the construction of the flow meter.
The dimensions and weight of the package depend on the
type and size of the ultrasonic gas flow meter and are to be
specified on the packing list.
If the FLC-UFL series flowmeter needs to be stored for a
certain period of time before installation, the following storage
conditions do apply:
■
Never stack the (packaged) flowmeters.
■
It is recommended to use a corrosion preventative coating
(oil, WD40, tectyl) on all bare metal parts of the flowcell
(e.g. inside, flange surfaces,...).
■
Be aware to remove the corrosion preventative coating
prior to putting the flowmeter in service.
■
Storage temperature: -30 °C to 60 °C.
■
Storage relative humidity: 5 – 95% RH, non-condensing
■
Use moisture absorbing bags (silica gel) inside the SPU to
protect the electronics from moisture.
■
Inspect the stored flowmeter on a regular basis to ensure
no condensation is present which may cause corrosion
and /or damage to the electronics.
■
When other piping components and/or flow conditioners
are provided with the meter, also apply a corrosion
preventative coating to any uncoated surfaces.
ATTENTION! - LONG TERM STORAGE
When the meter is stored for longer time, ensure
that the meter is stored in a sheltered condition
with a temperature between 0 °C and + 60 °C.
The inside of the Flowbody should be protected
from corrosion using a suitable corrosion
preventive coating.
