Dwyer UFM - Manual (Page 8)

F - UFM
Issue 1.4 Page 8
4.1 Preparation
1. Before attaching the transducers first ensure that the proposed location satisfies the
distance requirements shown in
Figure 3 otherwise the resulting accuracy of the flow readings
may be affected.
2. Prepare the pipe by degreasing it and removing any loose material or flaking paint in order
to obtain the best possible surface. A smooth contact between pipe surface and the face of
the transducers is an important factor in achieving a good ultrasound signal strength and
therefore maximum accuracy
.
4.2 Sensor separation
The sensor must be positioned at the correct distance for the pipe size and type they will be
used on. The table shown in Figure 4 gives the separation code for a given pipe material and
outside diameter. This code will be displayed whenever the pipe inside diameter and material
are prompted for.
Pipe Material
Plastic & Copper Steel
Minimum Maximum Minimum Maximum
B1 0.98 inches (24.9 mm) 1.22 inches (31.0 mm)
A2 1.22 inches (31.0 mm) 1.50 inches (38.1 mm) 0.98 inches (24.9 mm) 1.18 inches (30.0 mm)
C1 1.50 inches (38.1 mm) 1.69 inches (42.9 mm) 1.18 inches (30.0 mm) 1.42 inches (36.1 mm)
B2 1.69 inches (42.9 mm) 1.97 inches (50.0 mm) 1.42 inches (36.1 mm) 1.69 inches (42.9 mm)
A3 1.97 inches (50.0 mm) 2.20 inches (55.9 mm) 1.69 inches (42.9 mm) 1.93 inches (49.0 mm)
C2 2.20 inches (55.9 mm) 2.44 inches (62.0 mm) 1.93 inches (49.0 mm) 2.17 inches ( 55.1 mm)
B3 2.44 inches (62.0 mm) 2.68 inches (68.1 mm) 2.17 inches ( 55.1 mm) 2.40 inches (61.0 mm)
D2 2.68 inches (68.1 mm) 2.91 inches (73.9 mm) 2.40 inches (61.0 mm) 2.64 inches (67.0 mm)
C3 2.91 inches (73.9 mm) 3.15 inches (80.0 mm) 2.64 inches (67.0 mm) 2.87 inches (72.9 mm)
E2 3.15 inches (80.0 mm) 3.39 inches (86.1 mm) 2.87 inches (72.9 mm) 3.11 inches (79.0 mm)
D3 3.39 inches (86.1 mm) 3.66 inches (93.0 mm) 3.11 inches (79.0 mm) 3.35 inches (85.1 mm)
C4 3.66 inches (93.0 mm) 3.90 inches (99.0 mm) 3.35 inches (85.1 mm) 3.58 inches (90.9 mm)
E3 3.90 inches (99.0 mm) 4.13 inches (104.9 mm) 3.58 inches (90.9 mm) 3.82 inches (97.0 mm)
D4 4.13 inches (104.9 mm) 4.37 inches (111.0 mm) 3.82 inches (97.0 mm) 4.06 inches (103.1 mm)
F3 4.37 inches (111.0 mm) 4.53 inches (115.0 mm) 4.06 inches (103.1 mm) 4.29 inches (109.0 mm)
E4 4.53 inches (115.0 mm) 4.62 inches (117.3 mm) 4.29 inches (109.0 mm) 4.53 inches (115.0 mm)
D5 4.53 inches (115.0 mm) 4.62 inches (117.3 mm)
Figure 4 Separation Table
Pipe OD range (inches)