Dwyer Instruments UFM Operating Manual

F - UFM

UFM

Ultrasonic Flowmeter

User Manual

Issue 1.4 Page 1

F - UFM

Table of Contents

1 General Description ........................................................................................................................ 4

2 How does it work? .......................................................................................................................... 5

3 User interface .................................................................................................................................. 6

3.1 Key switches ............................................................................................................................ 6

4 Installing the UFM ........................................................................................................................... 7

4.1 Preparation ............................................................................................................................. 8

4.2 Sensor separation ................................................................................................................... 8

4.3 Adaptors for small pipes ....................................................................................................... 10

4.4 Attaching the UFM to the pipe ............................................................................................. 11

4.5 UFM interface cable .............................................................................................................. 12

4.6 Connecting the UFM to the Supply ....................................................................................... 12

4.7 Pulse Output connection ...................................................................................................... 12

4.8 Current Output ...................................................................................................................... 13

4.9 Cable Screen .......................................................................................................................... 13

5 Powering up for the first time ....................................................................................................... 14

5.1 How to enter the Pipe ID ...................................................................................................... 15

5.2 Pulse output .......................................................................................................................... 16

5.2.1 Volumetric mode .......................................................................................................... 16

5.2.2 Frequency mode ........................................................................................................... 16

5.3 4-20 mA Current output........................................................................................................ 16

6 Subsequent Power-ON Sequence ................................................................................................. 17

7 Password Controlled Menus ......................................................................................................... 17

7.1 General procedure for changing menu settings ................................................................... 17

7.1.1 Selection menus ............................................................................................................ 17

7.1.2 Data entry menus .......................................................................................................... 18

7.2 User Password controlled menu structure ........................................................................... 18

8 Diagnostics Menu .......................................................................................................................... 23

9 Relocation of guide rail ................................................................................................................. 24

10 Appendix I – UFM Specification ................................................................................................ 25

11 Appendix II – Default values ..................................................................................................... 26

12 Appendix III – Error and Warning Messages ............................................................................. 27

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12.1 System errors ........................................................................................................................ 27

12.2 Warnings ............................................................................................................................... 27

13 Maintenance/Repair ................................................................................................................. 28

14 Warranty /Return ...................................................................................................................... 28

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F - UFM

1 General Description

The UFM is a fixed installation, clamp-on flowmeter that is easy to install and requires minimum information to be entered by the user. Both the electronics and guide rail housings form an integral unit that is attached to the pipe using the supplied jubilee clips. Power to the unit is provided by an external 12 – 24 V ac/dc power supply. The UFM is intended to operate on steel, copper and plastic pipes with OD’s in the range 0.98 inches (24.9 mm) to 4.62 inches (117.4 mm).

Compact, rugged and reliable, the UFM has been designed to provide sustained performance in industrial environments.

UFM standard features include:

 2 line x 16 character LCD with backlight  4-key keypad  Isolated pulse output  4-20 mA current output  Simplified guide rail and transducer assembly  Continuous signal monitoring  Password protected menu operation for secure use  Operates from external 12 to 24 V ac/dc power supplies

 Small pipe adaptors

Typical applications

 Hot water metering and flow measurement  Flow measurement for heat metering  Chilled water metering and flow measurement  Potable water metering and flow measurement  Process water metering and flow measurement  Ultra pure water metering and flow measurement.

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F - UFM

Figure 1 Principle of Transit-Time operation

2 How does it work?

The UFM is a clamp-on, ultrasonic flowmeter that uses a multiple slope transit time algorithm to provide accurate flow measurements.

An ultrasonic beam of a given frequency is generated by applying a repetitive voltage pulse to the transducer crystals. This transmission goes first from the Downstream transducer to the Upstream transducer (red) as shown in the upper half of Figure 1. The transmission is then made in the reverse direction, being sent from the Upstream transducer (red) to the Downstream transducer (blue) as shown in the lower half of Figure 1. The speed at which the ultrasound is transmitted through the liquid is accelerated slightly by the velocity of the liquid through the pipe. The subsequent time difference T1 – T2 is directly proportional to the liquid flow velocity.

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F - UFM

Figure 2 UFM User Interface

Selection key. Allows the user to select between options on the display.

Used to increment the value of each digit in numeric entry fields.

Used to decrement the value of each digit in numeric entry fields.

Used to enter the selection displayed or terminate the data entry. Pressing this key will take the user to another menu or to the Flow Reading screen.

3 User interface

Figure 2 illustrates the UFM user interface comprising of :

 One 2 line x 16 character LCD with backlight  Four tactile key switches  Two LED’s

3.1 Key switches

4-20 mA LED is illuminated when the 4-20 mA output is ON

Pulse LED is illuminated when the Pulse output is ON

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F - UFM

Possible Air

Possible sludge

Guide rail

Uniform Flow Profile

Distorted Flow Profile

Flow

Valid transducer location

20 x Diameter

10 x Diameter

45°

4 Installing the UFM

Figure 3 Location of Transducers

In many applications an even flow velocity profile over a full 360° is unattainable due to the presence of air turbulence at the top of the flow and possibly sludge at the bottom of the pipe. Experience has shown that the most consistently accurate results are achieved when the transducer guide rails are mounted at 45° with respect to the top of the pipe.

The UFM equipment expects a uniform flow profile, as a distorted flow will produce unpredictable measurement errors. Flow profile distortions can result from upstream disturbance such as bends, tees, valves, pumps and other similar obstructions. To ensure a uniform profile the transducers must be mounted far enough away from any cause of distortion such that it no longer has an effect.

To obtain the most accurate results the condition of both the liquid and the pipe must be suitable to allow ultrasound transmission along the predetermined path. It is important that liquid flows uniformly within the length of pipe being monitored, and that the flow profile is not distorted by any upstream or downstream obstructions. This is best achieved by ensuring there is a straight length of pipe upstream of the transducers of at least 20 times the pipe diameter, and 10 times the pipe diameter on the downstream side, as shown in Figure 3. Flow measurements can be made on shorter lengths of straight pipe, down to 10 diameters upstream and 5 diameters downstream, but when the transducers are mounted this close to any obstruction the resulting errors can be unpredictable.

Key Point: Do not expect to obtain accurate results if the transducers are positioned close to any obstruction that distorts the uniformity of the flow profile.

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Pipe Material

Plastic & Copper

Steel

Minimum

Maximum

Minimum

Maximum

0.98 inches (24.9 mm)

1.22 inches (31.0 mm)

1.50 inches (38.1 mm)

0.98 inches (24.9 mm)

1.18 inches (30.0 mm)

1.50 inches (38.1 mm)

1.69 inches (42.9 mm)

1.18 inches (30.0 mm)

1.42 inches (36.1 mm)

1.69 inches (42.9 mm)

1.97 inches (50.0 mm)

1.42 inches (36.1 mm)

1.69 inches (42.9 mm)

1.97 inches (50.0 mm)

2.20 inches (55.9 mm)

1.69 inches (42.9 mm)

1.93 inches (49.0 mm)

2.20 inches (55.9 mm)

2.44 inches (62.0 mm)

1.93 inches (49.0 mm)

2.17 inches ( 55.1 mm)

2.44 inches (62.0 mm)

2.68 inches (68.1 mm)

2.17 inches ( 55.1 mm)

2.40 inches (61.0 mm)

2.68 inches (68.1 mm)

2.91 inches (73.9 mm)

2.40 inches (61.0 mm)

2.64 inches (67.0 mm)

2.91 inches (73.9 mm)

3.15 inches (80.0 mm)

2.64 inches (67.0 mm)

2.87 inches (72.9 mm)

3.15 inches (80.0 mm)

3.39 inches (86.1 mm)

2.87 inches (72.9 mm)

3.11 inches (79.0 mm)

3.39 inches (86.1 mm)

3.66 inches (93.0 mm)

3.11 inches (79.0 mm)

3.35 inches (85.1 mm)

3.66 inches (93.0 mm)

3.90 inches (99.0 mm)

3.35 inches (85.1 mm)

3.58 inches (90.9 mm)

3.90 inches (99.0 mm)

4.13 inches (104.9 mm)

3.58 inches (90.9 mm)

3.82 inches (97.0 mm)

4.13 inches (104.9 mm)

4.37 inches (111.0 mm)

3.82 inches (97.0 mm)

4.06 inches (103.1 mm)

4.37 inches (111.0 mm)

4.53 inches (115.0 mm)

4.06 inches (103.1 mm)

4.29 inches (109.0 mm)

4.53 inches (115.0 mm)

4.62 inches (117.3 mm)

4.29 inches (109.0 mm)

4.53 inches (115.0 mm)

4.62 inches (117.3 mm)

Pipe OD range (inches)

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.

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Figure 4 Separation Table

F - UFM

The diagram in figure 5 shows how to adjust the separation of the sensors

Figure 5 Separation Setting

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