AFLOWT UF-5 Series, Operation Manual

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7
2. CONFIGURING PRIOR TO OPERATION
2.1. Entering setting values for clamp-on PEAs
2.1.1. Open Settings / Main settings menu and enter:
- Transducer: Clamp-on
– PEA type
- Mount. mode: Z-mode or V-mode
– PEA mounting configuration.
Open Settings / Main settings / Install. settings menu and enter
the following setting values for each channel:
- Lcirc
– average outside diameter circumference of the pipeline section
- Do
– average outside diameter of the pipeline section
- Dtr
– average outside diameter of the pipeline section in the longitudinal
plane of PEAs
- Wall mat
– wall material of the pipeline section
- hw
– average outside diameter of the pipeline section
- Coat. mat.
– lining material of the pipeline section
- hcoat
– pipeline section lining thickness
- Axial dist. calc. submenu
- Lx
– measured distance between acoustic centres of the PEA pair
along the pipeline axis
- d
– value of equivalent asperity of the inner wall of the pipeline section
-

– kinematic viscosity of the liquid in the pipeline
- U
– phase velocity for the PEA pair.
Axial dist. calc. submenu is used to enter the ultrasound velocity
in the measured medium Cx and read the recommended value Lx .
2.2. Defining zero offset dT0
2.2.1. Zero offset dT0 shall be defined when the flow in the pipeline is fully
stopped. Open Settings menu and select Calibration / Zero calibra-
tion / Automated / Run calibr line. Start calibration procedure by se-
lecting Start value. After calibration is stopped (to do this assign Stop.
value to Run calibr setting) and the device returns to ZERO CALIBR.
chan. X window, dT0 setting will be automatically set to the value cal-
culated by the flowmeter.
In case it is impossible to absolutely stop the flow of liquid in the
pipeline, you may determine zero offset as follows:
- When the flowrate value lies in the range 0.1Qmax
– Qmax the
dT0 set-
ting is defined according to the foregoing procedure
– dT
01
- For clamp-on PEA pairs with connected cables are reciprocally
swapped instead.
The required value of zero offset is calculated from the formula:
dT
0
= 0.5 (

dT
01

–

dT
02

), µs. (1)
2.2.2. The calculated value is assigned to the dT0 setting in the flowmeter and
recorded to the log. After that, the initial installation of clamp-on PEAs is
restored.