Flexim FLUXUS F401 User manual

User Manual
UMFLUXUS_F4V1-3EN
Ultrasonic Flowmeter
for Water
FLUXUS F401

FLUXUS is a registered trademark of FLEXIM GmbH.
FLEXIM GmbH
Wolfener Straße 36
12681 Berlin
Germany
Tel.: [phone]
Fax: [phone]
Email: [email protected]
www.flexim.com
User manual for
FLUXUS F401
UMFLUXUS_F4V1-3EN, 2017-07-17
Firmware version: 6.28
Copyright (©) FLEXIM GmbH 2017
Subject to change without notification.

FLUXUS F401
UMFLUXUS_F4V1-3EN, 2017-07-17
Die Sprache, in der die Anzeigen auf dem Messumformer erscheinen, kann eingestellt
werden (siehe Abschnitt 9.6).
The transmitter can be operated in the language of your choice (see section 9.6).
Il est possible de sélectionner la langue utilisée par le transmetteur à l'écran (voir sec-
tion 9.6).
El caudalímetro puede ser manejado en el idioma de su elección (ver sección 9.6).
De transmitter kan worden gebruikt in de taal van uw keuze (zie gedeelte 9.6).
Имеется возможность выбора языка информации, отображаемой на экране
преобразователя (смотри подраздел 9.6).

UMFLUXUS_F4V1-3EN, 2017-07-17
FLUXUS F401

Table of Contents FLUXUS F401
UMFLUXUS_F4V1-3EN, 2017-07-17 5
Table of Contents
1Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.1 Regarding this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2 Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3 Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2 Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1 General Safety Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2 Intended Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3 Not Intended Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.4 Safety Instructions for the User . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.5 Safety Instructions for the Operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.6 Safety Instructions for Electrical Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.7 Safety Instructions for Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.8 Recommended Procedure in Hazardous Situations . . . . . . . . . . . . . . . . . . . . . 14
3Handling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.1 First Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 General Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.3 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.4 Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4 General Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1 Measurement System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.2 Measurement Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.3 Measurement Arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5 Description of the Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.1 Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.2 Status Indication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.3 Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6 Selection of the Measuring Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6.1 Acoustic Penetration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
6.2 Undisturbed Flow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6.3 Selection of the Measurement Arrangement Taking into Account 
the Measuring Range and the Measuring Conditions . . . . . . . . . . . . . . . . . . . . 29
6.4 Selection of the Sound Beam Plane near an Elbow . . . . . . . . . . . . . . . . . . . . . 30

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FLUXUS F401 Table of Contents
7 Installation of FLUXUS F401 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7.1 Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7.2 Connections of the Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
7.3 Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7.4 Connection of the Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
7.5 Connection of the Serial Interface RS232 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
7.6 Connection of the Serial Interface RS485 (optional) . . . . . . . . . . . . . . . . . . . . . 36
8 Mounting of the Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
8.1 Preparation of the Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
8.2 Orientation of the Transducers and Transducer Distance . . . . . . . . . . . . . . . . . 37
8.3 Mounting of the Transducers with Transducer Clamping Fixture and Ladder . . . .
Chains38
8.4 Mounting of the Transducers with Transducer Shoe and Ball Chains . . . . . . . . 39
8.5 Mounting of the Transducers with Transducer Shoes and Ladder Chains . . . . . 40
9 Start-Up of the Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
9.1 Start-up settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
9.2 Switching On. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
9.3 Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
9.4 Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
9.5 HotCodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
9.6 Language Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
10 Basic Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
10.1 Input of the Pipe Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
10.2 Input of the Fluid Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
10.3 Selection of the Transducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
10.4 Input of the Measuring Point Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
10.5 Defining the Number of Sound Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
10.6 Transducer Distance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
10.7 Start of the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
10.8 Detection of the Flow Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
10.9 Stopping the Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
11 Displaying the Measured Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
11.1 Selection of the Physical Quantity and of the Unit of Measurement. . . . . . . . . . 54
11.2 Adjustment of the Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
11.3 Status Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
11.4 Transducer Distance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Table of Contents FLUXUS F401
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12 Advanced Measuring Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
12.1 Command Execution during Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
12.2 Damping Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
12.3 Totalizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
12.4 Upper Limit of the Flow Velocity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
12.5 Cut-Off Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
12.6 Uncorrected Flow Velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
12.7 Program Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
12.8 Diagnosis with by means of the Snap Function . . . . . . . . . . . . . . . . . . . . . . . . . 65
13 Data Logger and Transmission of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
13.1 Data Logger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
13.2 Transmission of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
14 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
14.1 Time and Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
14.2 Dialogs and Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
14.3 Measurement Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
14.4 Setting the Contrast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
14.5 Instrument Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
15 SuperUser-Modus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
15.1 Activation/Deactivation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
15.2 Defining Flow Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
15.3 Limit of the Signal Amplification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
15.4 Upper Limit of the Sound Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
15.5 Detection of Long Measurement Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
15.6 Number of Decimal Places of the Totalizers . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
15.7 Manual Reset of the Totalizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
15.8 Display of the Sum of the Totalizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
15.9 Display of the Last Valid Measured Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
15.10 Display During the Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
16 Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
16.1 Installation of an Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
16.2 Error Value Delay. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
16.3 Activation of an Analog Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
16.4 Activation of a Binary Output as a Pulse Output . . . . . . . . . . . . . . . . . . . . . . . . 99
16.5 Activation of a Binary Output as an Alarm Output . . . . . . . . . . . . . . . . . . . . . . . 99
16.6 Behavior of the Alarm Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
16.7 Deactivation of the Alarm Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

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FLUXUS F401 Table of Contents
17 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
17.1 Problems with the Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
17.2 Selection of the Measuring Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
17.3 Maximum Acoustic Contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
17.4 Application Specific Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
17.5 Large Deviations of the Measured Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
17.6 Problems with the Totalizers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
17.7 Transmission of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Annex
A Menu Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
B Units of Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
C Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
D Conformity Declarations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

1 Introduction FLUXUS F401
UMFLUXUS_F4V1-3EN, 2017-07-17 9
1 Introduction
1.1 Regarding this Manual
This user manual has been written for the users operating the ultrasonic flowmeter
FLUXUS. It contains important information about the measuring instrument, how to han-
dle it correctly, and how to avoid damages.
Read the safety Instructions carefully. Make sure you have read and understood this
user manual before using the measuring instrument.
All reasonable effort has been made to ensure the correctness of the content of this user
manual. However, If you find any erroneous information, please inform us. We will be
grateful for any suggestions and comments regarding the concept and your experience
working with the measuring instrument.
This will ensure that we can further develop our products for the benefit of our customers
and in the interest of technological progress. If you have any suggestions about improv-
ing the documentation and particularly this user manual, please let us know so that we
can consider your comments for future reprints.
The contents of this user manual are subject to changes without prior notice. All rights re-
served. No part of this user manual may be reproduced in any form without FLEXIM's
written permission.
1.2 Safety Instructions
The user manual contains instructions that are marked as follows:
Observe these safety instruction!
Note! For technical data see Technical specification.
Note! This text contains important information about the use of the flow-
meter.
Attention! This text contains important instructions which should be observed
to avoid damage or destruction of the measuring instrument. Pro-
ceed with special caution!

10 UMFLUXUS_F4V1-3EN, 2017-07-17
FLUXUS F401 1 Introduction
1.3 Warranty
We warrant the reliability of the material and workmanship of FLUXUS for the term spec-
ified in the sales contract, provided the measuring instrument is used for the purpose for
which it was designed, and operated according to the instructions given in this user man-
ual. Improper use of the FLUXUS leads to the withdrawal of any warranties of any kind,
explicit or implicit.
Incorrect use includes:
• replacement of a component of FLUXUS with a component that was not approved by
FLEXIM
• unsuitable or insufficient maintenance
• repair of FLUXUS by unauthorized personnel
FLEXIM assumes no responsibility for injuries to the customer or third persons directly
caused by material failure due to unpredictable defects in the product or for any indirect
damages.
FLUXUS is a very reliable instrument. It is manufactured under strict quality control using
modern production techniques. If installed as recommended in an appropriate location,
used cautiously and taken care of conscientiously, no troubles should appear.
If any problem appears which cannot be solved with the help of this user manual (see
chapter 17), contact our sales office and give a precise description of the problem. Spec-
ify the type, serial number and firmware version of the measuring instrument.

2 Safety Instructions FLUXUS F401
UMFLUXUS_F4V1-3EN, 2017-07-17 11
2 Safety Instructions
2.1 General Safety Instructions
Prior to any work, read the user manual carefully and in full.
Failure to comply with the instructions, in particular with the safety instructions, poses a
risk to health and can lead to material damages. For further information, contact FLEXIM.
During installation and operation of the measuring equipment, observe the ambient and
installation conditions specified in the documentation.
The measuring equipment has to be checked for proper condition and operational safety
before each use.The measuring equipment has to be checked for proper condition and
operational safety before each use. If disturbances or damages have occurred during in-
stallation or operation of the measuring equipment, please inform FLEXIM.
It is not allowed to make unauthorized modifications or alterations to the measuring
equipment.
The personnel has to be suitably trained and experienced for the work.
2.2 Intended Use
The measuring equipment is intended for the measurement of fluid properties in closed
pipes. By means of connected transducers, the transit times of the ultrasonic signals in
the fluid and the pipe as well as other related properties, such as temperature and pres-
sure, are measured and evaluated.
The transmitter uses these values to calculate the sought quantities, e.g., volumetric flow
rate, mass flow rate, heat quantity, density and concentration. Through comparison with
the values stored in the transmitter further physical quantities can be determined. The
physical quantities are provided via configurable outputs and the display.
• All instructions of this user manual have to be observed to ensure intended use.
• Any use beyond or other than the intended use is not covered by warranty and can
present a danger. Any damage arising from not intended use shall be solely the liability
of the operator or user.
• The measurement is carried out without direct contact to the fluid in the pipe. The flow
profile is not influenced.
• The transducers are fixed to the pipe using the supplied transducer mounting fixture.
• Observe the operating conditions, e.g., environment, voltage ranges. For the technical
data of the transmitter, transducers and accessories, see Technical specification.

12 UMFLUXUS_F4V1-3EN, 2017-07-17
FLUXUS F401 2 Safety Instructions
2.3 Not Intended Use
Not intended use in terms of a misuse means:
• any work on the measuring equipment without observing all instructions in this user
manual
• use of transmitter, transducer and accessories combinations not intended by FLEXIM
• use in explosive atmospheres (the transmitter is not certificated for these atmospheres
and should not be used there)
• any work on the measuring equipment (e.g., installation, dismounting, connection, start-
up, operation, service and maintenance) carried out by unauthorized and untrained per-
sonnel
• storage, installation and operation of the measuring equipment outside the specified
ambient conditions, see section 7.3.2 and Technical specification
2.4 Safety Instructions for the User
Any work on the transmitter has to be carried out by authorized and qualified personnel.
Observe the safety instructions in the user manual. For the technical data of the transmit-
ter, transducers and accessories, see Technical specification.
• Observe the safety and accident prevention regulations applicable on the site of opera-
tion.
• Only use the supplied mounting fixtures and transducers as well as the intended acces-
sories.
• Always wear the required personal protective equipment.
2.5 Safety Instructions for the Operator
• The operator shall qualify the personnel to perform their assigned tasks. They shall pro-
vide the required personal protective equipment and oblige the personnel to wear it. It is
recommended to risk assess the workplace.
• Besides the safety instructions in this user manual, the health, safety and environment
regulations applicable for the range of application of the transmitter, transducers and
accessories have to be observed.
• With the exceptions stated in chapter 17, the measuring equipment is maintenance-
free. Any components and spare parts may only be replaced by FLEXIM. The operator
shall carry out periodic checks for changes or damages that can present a danger. For
further information, contact FLEXIM.
• Observe the specifications for the installation and connection of the transmitter, trans-
ducers and accessories (see chapter 7 and chapter 8).

2 Safety Instructions FLUXUS F401
UMFLUXUS_F4V1-3EN, 2017-07-17 13
2.6 Safety Instructions for Electrical Work
• Electrical work may only be carried out if there is enough space.
• The degree of protection of the transmitter is only ensured if the cables are firmly con-
nected to the transmitter and all unused connections are covered.
• The condition and tight fit of the electrical connections have to be checked at regular in-
tervals.
• The power supply unit for charging the battery, may only be connected to networks up
to overvoltage category II. Use only the supplied power supply unit. For the power sup-
ply via power cable and power adapter, observe the safety instructions in section 7.3.1.
• The transmitter and the power supply unit must not be disassembled, see Fig. 2.1. The
transmitter does not contain any components to be maintained by the user. For repair
and service work, please contact FLEXIM.
• Observe the safety and accident prevention regulations for electrical systems and
equipment.
Fig. 2.1: Transmitter FLUXUS F401

14 UMFLUXUS_F4V1-3EN, 2017-07-17
FLUXUS F401 2 Safety Instructions
2.7 Safety Instructions for Transport
• If you detect a transport damage when unpacking the delivery, please contact the sup-
plier or FLEXIM immediately.
• The transmitter is a sensitive electronic measuring instrument. Avoid shocks or impacts.
• Handle the transducer cable with care. Avoid sharp bends or kinks. Observe the ambi-
ent conditions.
• Select a solid surface to put the transmitter, transducers and accessories on.
• The transmitter, transducers and accessories have to be properly packed for transport:
– Use, if possible, the original packaging by FLEXIM or an equivalent cardboard box.
– Position the transmitter, transducers and accessories in the middle of the cardboard
box.
– Fill any voids with appropriate packaging material (e.g., paper, foam, bubble wrap).
– Protect the cardboard box against humidity.
2.8 Recommended Procedure in Hazardous Situations
Fire Fighting Measures
• If possible, disconnect the transmitter from the power supply.
• Prior to extinguishing, protect any electrical parts that are not affected by the fire (e.g.,
using a cover).
• Select a suitable extinguishing agent. Avoid, if possible, conductive extinguishing
agents.

3 Handling FLUXUS F401
UMFLUXUS_F4V1-3EN, 2017-07-17 15
3Handling
3.1 First Inspection
The measuring instrument has already been tested thoroughly at the factory. At delivery,
proceed to a visual control to make sure that no damage has occurred during transportation.
Make sure that the specifications of the delivered measuring instrument correspond to
the specifications given on the purchase order.
The type and the serial number of the transmitter are shown on the nameplate. The
transducer type is printed on the transducers.
3.2 General Precautions
FLUXUS is a precision measuring instrument and has to be handled with care. In order to
obtain good measurement results and not damage the measuring instrument, it is import-
ant to pay special attention to the instructions given in this user manual, particularly to the
following points:
• Protect the transmitter from shocks.
• Keep the transducers clean. Handle the cables with care. Avoid excessive cable bend.
• Make sure to work under correct ambient and operating temperatures. The ambient
temperature at the measuring point has to be within the operating temperature range of
the transmitter and the transducers (see Technical specification).
• Observe the degree of protection (see Technical specification).
3.3 Cleaning
• Clean the transmitter with a soft cloth. Do not use detergents.
• Remove traces of the coupling compound from the transducers with a soft paper towel.
3.4 Storage
• Wipe the transducers clean of traces of the coupling compound.
• After the measurement, always put the transmitter and its accessories into the corre-
sponding backpack.
• Avoid excessive cable bends.
• Observe the notes on the storage of the battery (see Storage of the Battery in section
7.3.2).

16 UMFLUXUS_F4V1-3EN, 2017-07-17
FLUXUS F401 4 General Principles
4 General Principles
For the ultrasonic measurement of the flow rate, the flow velocity of the fluid in a pipe is
determined. Further physical quantities (e.g., volumetric flow rate, mass flow rate) are
derived from the flow velocity and from additional physical quantities, if necessary.
4.1 Measurement System
The measurement system consists of a transmitter, the ultrasonic transducers with the
transducer cables and the pipe on which the measurement is conducted.
The ultrasonic transducers are mounted on the outside of the pipe. Ultrasonic signals are
sent through the fluid and received by the transducers. The transmitter controls the mea-
suring cycle, eliminates the disturbance signals and analyzes the useful signals. The
measured values can be displayed, used for calculations and transmitted.
4.2 Measurement Principle
The flow velocity of the fluid is measured using the ultrasonic-transit time difference cor-
relation principle (see section 4.2.2).
4.2.1 Terms
Flow profile
Distribution of the flow velocities over the cross-sectional pipe area. For an optimal mea-
surement, the flow profile has to be fully developed and axisymmetrical. The shape of the
flow profile depends on whether the flow is laminar or turbulent and is influenced by the
conditions in the supply line of the measuring point (see chapter 6).
Fig. 4.1: Example of a measurement setup
transducers
transmitter
pipe

4 General Principles FLUXUS F401
UMFLUXUS_F4V1-3EN, 2017-07-17 17
Reynolds number Re
Coefficient describing the turbulence behavior of a fluid in the pipe. The Reynolds num-
ber Re is calculated from the flow velocity, the kinematic viscosity of the fluid and the in-
ner pipe diameter.
If the Reynolds number exceeds a critical value (usually approx. 2 300, if the fluid flows in
a pipe), a transition from a laminar flow to a turbulent flow takes place.
Laminar flow
A flow without any turbulence. There is no disruption between the parallel flowing layers
of the fluid.
Turbulent flow
A flow in which turbulence (swirling of the fluid) occurs. In technical applications, the flow
in the pipe is mostly turbulent.
Transition range
The flow is partly laminar and partly turbulent.
Transit time difference ∆t
Difference of the transit times of the signals in and against the flow direction. The flow ve-
locity of the fluid flowing in the pipe is determined from the transit time difference (see
Fig. 4.2, Fig. 4.3, Fig. 4.4).
Sound speed c
Speed of the propagating sound. The sound speed depends on the mechanical proper-
ties of the fluid or the pipe material. In pipe materials and other solid materials, a distinc-
tion is made between the longitudinal and transversal sound speed. For the sound speed
of some fluids and materials see annex C.
Flow velocity v
Average value of all flow velocities of the fluid over the cross-sectional pipe area.
Acoustic calibration factor ka
ka=
The acoustic calibration factor kais a parameter of the transducer which results from the
sound speed c within the transducer and the angle of incidence (see Fig. 4.2). According
to Snell's law of refraction, the angle of propagation in the adjoining fluid or pipe material
is:
ka= = =
c
sin
------------
c
sin
------------
c
sin
------------
c
sin
-----------

18 UMFLUXUS_F4V1-3EN, 2017-07-17
FLUXUS F401 4 General Principles
Fluid mechanics correction factor kRe
With the fluid mechanics correction factor kRe, the measured value of the flow velocity in
the area of the sound beam is converted into the value of the flow velocity across the
whole cross-sectional pipe area. In case of a fully developed flow profile, the fluid me-
chanics correction factor only depends on the Reynolds number and the roughness of
the inner pipe wall. The fluid mechanics correction factor is recalculated by the transmit-
ter for each new measurement.
Volumetric flow rate
= v · A
The volume of the fluid that passes through the pipe per unit time. The volumetric flow
rate is calculated from the product of the flow velocity v and the cross-sectional pipe area
A.
Mass flow rate
= · ρ
The mass of the fluid that passes through the pipe per unit time. The mass flow rate is
calculated from the product of the volumetric flow rate and the density ρ.
4.2.2 Measurement of the Flow Velocity
The signals are emitted and received by two transducers alternatively in and against the
flow direction. If the fluid moves, the signals propagating in the fluid are displaced with
the flow. This displacement causes a reduction in distance for the signal in the flow direc-
tion and an increase in distance for the signal against the flow direction in the section of
the receiving transducer (see Fig. 4.2 and Fig. 4.3). This causes a change in the transit
times. The transit time of the signal in the flow direction is shorter than the transit time
against the flow direction. This transit time difference is proportional to the average flow
velocity.
The average flow velocity of the fluid is calculated as follows:
V = kRe . ka.
with
v – average flow velocity of the fluid
kRe – fluid mechanics correction factor
ka– acoustic calibration factor
∆t – transit time difference
tγ– transit time in the fluid
V
·
V
·
m
·
m
·
V
·
V
·
t
2t


-----------

4 General Principles FLUXUS F401
UMFLUXUS_F4V1-3EN, 2017-07-17 19
Fig. 4.2: Sound path of the signal in the flow direction.
Fig. 4.3: Sound path of the signal against the flow direction
Fig. 4.4: Signals and transit time difference ∆t
transducer (emitter)
flow direction
of the fluid
sound path without flow
sound path with flow
pipe wall
α
β
γ
cα cα
cγ
cβ
transducer (receiver)
reduction in distance
in the transducer
flow direction
of the fluid
sound path without flow sound path with flow
α
β
γ
cα
cα
cγ
cβ
increase in distance
in the transducer
pipe wall
transducer (receiver) transducer (emitter)
∆t
signal in the
flow direction
signal against
the flow direction

20 UMFLUXUS_F4V1-3EN, 2017-07-17
FLUXUS F401 4 General Principles
4.3 Measurement Arrangements
4.3.1 Terms
Diagonal arrangement
The transducers are mounted on the opposite sides of the pipe (see Fig. 4.5).
Reflection arrangement
The transducers are mounted on the same side of the pipe (see Fig. 4.6).
Sound path
The distance covered by the ultrasonic signal after crossing the pipe once. The number
of the sound paths is:
• odd if the measurement is conducted in the diagonal arrangement
• even if the measurement is conducted in the reflection arrangement
Transducer distance
Distance between the transducers. It is measured between the inner edges of the trans-
ducers.
Fig. 4.5: Diagonal arrangement Fig. 4.6: Reflection arrangement
reflection arrangement
diagonal arrangement
(positive transducer distance)
transducer distance
transducer distance