Flexim FLUXUS G831ST-HT User manual

FLUXUS G831ST-HT
UMFLUXUS_G831ST-HTV1-0EN
Operating instruction

FLEXIM GmbH
Boxberger Straße 4
12681 Berlin
Germany
Tel.: [phone]
Fax: [phone]
E-mail: [email protected]
www.flexim.com
FLUXUS is a registered trademark of FLEXIM GmbH.
Operating instruction for
FLUXUS G831ST-HT
UMFLUXUS_G831ST-HTV1-0EN, 2021-06-01
Article number: 22811
Copyright (©) FLEXIM GmbH 2021
Subject to change without prior notice.

FLUXUS G831ST-HT Table of contents
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Table of contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2 Safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
2.1 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
2.2 Intended use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
2.3 Not intended use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
2.4 Safety instructions for the user . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
2.5 Safety instructions for the operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
2.6 Safety instructions for electrical work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
2.7 Safety instructions for transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.8 Recommended procedure in hazardous situations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
3 General principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
3.1 Measurement principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
3.2 Measurement arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3.3 Acoustic penetration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.4 Undisturbed flow profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
4 Product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
4.1 Measuring system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
4.2 Handling concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
4.3 Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
4.4 Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
5 Transport and storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
5.1 Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
5.2 Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
6 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
6.1 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
6.2 Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
6.3 Temperature probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
7 Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49
7.1 Transducers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
7.2 Power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
7.3 Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
7.4 Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
7.5 Temperature probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
7.6 Service interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68
8 Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
8.1 Start-up settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
8.2 Switching on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
8.3 Program branches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
8.4 Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
8.5 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
8.6 Date and time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
8.7 Information regarding the transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

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9 Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
9.1 Parameter input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
9.2 Measurement settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
9.3 Start of the measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
9.4 Display of measured values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
9.5 Display of parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
9.6 Repeated display of measured values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
9.7 Execution of special functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
9.8 Stop of the measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
10 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
10.1 Problems with the measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
10.2 Measuring point selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
10.3 Maximum acoustic contact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
10.4 Application-specific problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
10.5 Significant deviations of the measured values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
10.6 Problems with the totalizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
11 Maintenance and cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
11.1 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
11.2 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
11.3 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
11.4 Examination of the O-ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
11.5 Examination of the thread on the flameproof enclosure housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
11.6 Examination of housing and sight glass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
11.7 Firmware update . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
12 Dismounting and disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
12.1 Dismounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
12.2 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
13 User modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
13.1 StandardUser mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
13.2 ExpertUser mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
13.3 SuperUser mode and SuperUser ext. mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
14 Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
14.1 Configuration of an input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
14.2 Assignment of an input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
15 Data logger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
15.1 Configuration of the data logger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
15.2 Deletion of the data logger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
15.3 Information regarding the data logger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
16 Data transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
16.1 Service interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

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17 Advanced functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121
17.1 Totalizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121
17.2 Diagnosis with the help of the snap function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124
17.3 Modification of the limit for the inner pipe diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125
17.4 Remote functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126
17.5 Event triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127
17.6 Event protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .131
18 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132
18.1 Dialogs and menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132
18.2 Measurement settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134
18.3 Units of measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135
18.4 Material and fluid scroll list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135
18.5 Working with parameter records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .136
18.6 Contrast settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137
18.7 HotCodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137
18.8 Key lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138
Annex
A Menu structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .141
B Units of measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154
C Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157
D Terminal assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158

Table of contents FLUXUS G831ST-HT
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1 Introduction
FLUXUS G831ST-HT
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1 Introduction
This operating instruction has been written for users operating the ultrasonic flowmeter FLUXUS. It contains important
information about the measuring equipment, how to handle it correctly, and how to avoid damages. Read the safety
instructions carefully. Make sure you have read and understood this operating instruction before using the measuring
equipment.
Any work on the measuring equipment has to be carried out by authorized and qualified personnel in order to detect and
avoid possible risks and dangers.
Presentation of warnings
This operating instruction contains warnings marked as follows:
Storage of the operating instruction
The operating instruction must permanently be available at the place where the measuring equipment is used. It must
always be available to the user.
User comments
All reasonable effort has been made to ensure the correctness of the content of this operating instruction. If you, however,
find some erroneous information or miss information, please inform us.
We will be grateful for any suggestions and comments regarding the concept and your experience working with the
measuring equipment. If you have any suggestions about improving the documentation and particularly this operating
instruction, please let us know so that we can consider your comments for future reprints.
Copyright
The contents of this operating instruction are subject to changes without prior notice. All rights reserved. No part of this
operating instruction may be reproduced in any form without FLEXIM's written permission.
Danger!
Type and source of danger
danger with high level of risk, which, if not avoided, can lead to death or serious injuries
→ measures of prevention
Warning!
Type and source of danger
danger with medium level of risk, which, if not avoided, can lead to serious or moderate injuries
→ measures of prevention
Caution!
Type and source of danger
danger with low level of risk, which, if not avoided, can lead to moderate or minor injuries
→ measures of prevention
Important!
This text contains important information which should be observed to avoid material damage.
Notice!
This text contains important information about the handling of the measuring equipment.

2 Safety instructions
2.1 General safety instructions FLUXUS G831ST-HT
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2 Safety instructions
2.1 General safety instructions
Prior to any work, read the operating instruction 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.
Explanation of symbols on the transmitter:
The measuring equipment has to be checked for proper condition and operational safety before each use. If troubles or
damages have occurred during installation or operation of the measuring equipment, please inform FLEXIM.
It is not allowed to make unauthorized modifications or alterations to the measuring equipment.
If the measuring point is within an explosive atmosphere, the danger zone and present explosive atmosphere have to be
determined. The transmitter, transducers and accessories have to be appropriate and approved for the conditions within
the corresponding zone.
The personnel has to be suitably trained and experienced for the work.
Observe the "Safety instructions for the use in explosive atmospheres" (see document SIFLUXUS). Observe the instructions
for hazardous substances and the respective safety data sheets. Observe the regulations for the disposal of electrical
equipment.
symbol explanation
direct current
connection to ground
ground conductor terminal
warning of voltage
observe the operating instruction
Attention!
i

2 Safety instructions
FLUXUS G831ST-HT 2.2 Intended use
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2.2 Intended use
The measuring equipment is intended for the measurement of fluid properties in closed pipes. The connected transducers
measure the average flow velocity of the fluid.
The transmitter uses these values to calculate the sought quantities, e.g., volumetric flow rate and mass flow rate.
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 operating instruction 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.
• If an extension cable is required to connect the transducers to the transmitter, a junction box can be used (optional).
Observe the safety instructions in the operating instruction. For the technical data of the junction box, see technical
specification.
• Observe the operating conditions, e.g., environment, voltage ranges. For the technical data of the transmitter,
transducers and accessories, see technical specification.
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 operating instruction
• use of transmitter, transducer and accessory combinations not intended by FLEXIM
• installation of the transmitter, transducers and accessories in explosive atmospheres they are not approved for
• any work on the measuring equipment (e.g., installation, dismounting, connection, start-up, operation, service and
maintenance) carried out by unauthorized and untrained personnel
• storage, installation and operation of the measuring equipment outside the specified ambient conditions (see 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 operating instruction. For the technical data of the transmitter, transducers and accessories, see technical
specification.
• Observe the safety and accident prevention regulations applicable on the site of operation.
• Only use the supplied mounting fixtures and transducers as well as the intended accessories.
• 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. The operator shall provide 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 operating instruction, 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 11, 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, transducers and accessories.

2 Safety instructions
2.6 Safety instructions for electrical work FLUXUS G831ST-HT
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2.6 Safety instructions for electrical work
• Prior to any work on the transmitter (e.g., installation, dismounting, connection, service and maintenance), the
transmitter has to be disconnected from the power supply.
• Electrical work may only be carried out if there is enough space.
• Open the transmitter in safe ambient conditions only (e.g., air humidity < 90 %, no conductive pollution, no explosive
atmosphere).
• The degree of protection of the transmitter is only ensured if all cables are tightly fitted using cable glands and the
housing is firmly screwed.
• The condition and tight fit of the electrical connections have to be checked at regular intervals.
• When connecting the transmitter to the power supply, an appropriate equipment switch according to IEC 60947-1 and
IEC 60947-3 has to be installed as disconnecting device. The equipment switch has to disconnect all live wires. The
ground conductor connection must not be interrupted. The equipment switch has to be easily accessible and clearly
marked as a disconnecting device for the transmitter. It should be located near the transmitter. If the transmitter is used
in an explosive atmosphere, the equipment switch has to be installed outside the explosive atmosphere. If this is not
possible, it has to be installed in the least hazardous area.
• The connection may only be made to networks up to overvoltage category II. When connecting the inputs and outputs as
well as the power supply, observe the installation instructions, in particular the terminal assignment.
• The module must not be removed from the housing. 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
ENTER
CH BCH A
BRKCLR
Ulrasonic Flowmeter
module

2 Safety instructions
FLUXUS G831ST-HT 2.7 Safety instructions for transport
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2.7 Safety instructions for transport
• If you detect a transport damage when unpacking the delivery, please contact the supplier or FLEXIM immediately.
• The transmitter is a sensitive electronic measuring instrument. Avoid shocks or impacts.
• Handle the transducer cable with care. Avoid excessive bending or buckling. Observe the ambient 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.
• Observe the applicable minimum distances. The minimum distances differ depending on the used extinguishing agent.
Caution!
Warning of injuries due to falling objects
Unsecured and falling objects can lead to severe injuries.
→ Secure all components against falling during transport.
→ Wear the required personal protective equipment.
→ Observe the applicable rules.

3 General principles
3.1 Measurement principle FLUXUS G831ST-HT
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3 General principles
In the ultrasonic flow measurement, the flow velocity of the fluid in a pipe is determined. Further physical quantities are
derived from the flow velocity and from additional physical quantities, if necessary.
3.1 Measurement principle
3.1.1 Terms
Flow profile
Distribution of flow velocities over the cross-sectional pipe area. For an optimal measurement, 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 at the inlet of the measuring point.
Reynolds number Re
Coefficient describing the turbulence behavior of a fluid in the pipe. The Reynolds number Re is calculated from the flow
velocity, the kinematic viscosity of the fluid and the inner pipe diameter.
If the Reynolds number exceeds a critical value (usually approx. 2300, 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 mixing between the parallel flowing layers of the fluid.
Turbulent flow
A flow with turbulences (swirling of the fluid). In technical applications, the flow in the pipe is mostly turbulent.
Transition range
The flow is partly laminar and partly turbulent.
Flow velocity v
Average value of all flow velocities of the fluid over the cross-sectional pipe area.
Fluid mechanics calibration factor kRe
With the fluid mechanics calibration 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 mechanics calibration factor only depends on the Reynolds number and the roughness of the inner pipe
wall. The fluid mechanics calibration factor is recalculated by the transmitter for each new measurement.
Operating volumetric flow rate
= v · A
The volume of the fluid that passes through the pipe per unit time. The operating 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.
V
·
V
·
m
·
m
·V
·
V
·

3 General principles
FLUXUS G831ST-HT 3.1 Measurement principle
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3.1.2 Measurement of the flow velocity
The flow velocity of the fluid is measured using the correlation principle. 2 pairs of ultrasonic transducers of the same type
are mounted one after the other at a distance Δx on the pipe which is completely filled with the fluid. The transducer pairs
form the measuring barriers A and B. Ultrasonic signals are alternately emitted by the emitters A1 and B1 and received by
the respective receivers A2 and B2. The ultrasonic signals are modulated regarding amplitude and phase by the swirls of
the turbulent flowing fluid. Since the swirls move with the flow, they pass the measuring barriers A and B with a time
offset Δt, so that the modulation patterns of the ultrasonic signals of measuring barrier A and B are also offset by Δt. This
time offset Δt is measured by means of cross correlation of the modulation signals. The average flow velocity can be
calculated using the fluid mechanics calibration factor.
v = kRe ·
where
v – average flow velocity of the fluid
kRe – fluid mechanics calibration factor
Δx – distance between measuring barriers
Δt – time offset of the modulation patterns
Fig. 3.1: Measurement arrangement of the correlation principle
A1– emitter of measuring barrier A
A2– receiver of measuring barrier A
B1– emitter of measuring barrier B
B2– receiver of measuring barrier B
Δx – distance between measuring barriers
Fig. 3.2: Time offset of the modulation signals Δt
A – modulation signal of measuring barrier A
B – modulation signal of measuring barrier B
x
t
-------
A1B1
A2B2
Δx
flow direction
of the fluid
AB
Δt time
modulation

3 General principles
3.2 Measurement arrangements FLUXUS G831ST-HT
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3.2 Measurement arrangements
3.2.1 Terms
The transducers of a measuring barrier are mounted on opposite sides of the pipe.
Sound path
The distance covered by the ultrasonic signal of a transducer pair after crossing the pipe once.
Distance between the measuring barriers
The measuring barrier distance is measured between the inner edges of the emitters and/or receivers of measuring
barrier A and B.
Transducer distance
The transducer distance is measured between the inner edges of the transducers of a transducer pair.
Fig. 3.3: Diagonal arrangement with 2 parallel beams and 1 sound path each
Δx – measuring barrier distance
a – transducer distance
diagonal arrangement
(positive transducer distance)
diagonal arrangement
(negative transducer distance)
a – transducer distance
A1B1
A2B2
Δx
Δx
aa
a
a

3 General principles
FLUXUS G831ST-HT 3.3 Acoustic penetration
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Sound beam plane
Plane containing the sound paths of the measuring barriers.
3.3 Acoustic penetration
The pipe has to be acoustically penetrable at the measuring point. The acoustic penetration is given when pipe and fluid
do not attenuate the sound signal so strongly that it is completely absorbed before reaching the second transducer.
The attenuation caused by the pipe and the fluid depends on:
• kinematic viscosity of the fluid
• proportion of liquids and solids in the fluid
• deposits on the inner pipe wall
• pipe material
The following requirements have to be met at the measuring point:
• no solid deposits in the pipe
• no accumulation of liquid (condensate), e.g., before orifice plates or at pipe sections located lower
Observe the following notes on the selection of the measuring point:
Horizontal pipe
Select a measuring point where the transducers can be mounted laterally on the pipe, allowing the sound waves to
propagate horizontally in the pipe. Thus, solids or liquid on the bottom of the pipe are prevented from influencing the
propagation of the signal.
3.4 Undisturbed flow profile
Some flow elements (e.g., elbows, valves, pumps, reducers) distort the flow profile in their vicinity. The axisymmetrical
flow profile in the pipe needed for correct measurement is no longer given. A careful selection of the measuring point helps
to reduce the impact of disturbances.
It is most important that the measuring point is chosen at a sufficient distance from any disturbances. Only then it can be
assumed that the flow profile in the pipe is fully developed. However, measuring results can be obtained even if the
recommended distance to disturbances cannot be met for practical reasons (no ideal inflow, see section 13.2.3).
The recommended straight inlet and outlet pipe lengths for different types of flow disturbances are shown in the following
table.
Fig. 3.4: 2 sound paths in 1 plane
Fig. 3.5: Recommended transducer
mounting position (laterally)
Fig. 3.6: Disadvantageous transducer
mounting position (on top)

3 General principles
3.4 Undisturbed flow profile FLUXUS G831ST-HT
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Tab. 3.1: Recommended distance from disturbances
D – nominal pipe diameter at the measuring point
l – recommended distance between disturbance and transducer position
disturbance: 90° elbow
inlet: l ≥ 10 D outlet: l ≥ 5 D
disturbance: 2 × 90° elbow on different planes
inlet: l ≥ 40 D outlet: l ≥ 5 D
disturbance: valve
inlet: l ≥ 40 D outlet: l ≥ 5 D
disturbance: reducer
inlet: l ≥ 10 D outlet: l ≥ 5 D
disturbance: compressor
inlet: l ≥ 20 D
l l
l l
l l
l l
l

4 Product description
FLUXUS G831ST-HT 4.1 Measuring system
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4 Product description
4.1 Measuring system
The measurement system consists of the transmitter, 2 pairs of ultrasonic transducers and the pipe on which the
measurement is carried out.
4.2 Handling concept
The command panel is on the front side of the upper housing. The keys are operated using a magnetic pen with the
housing being closed.
By pressing the following program branches are displayed consecutively:
•Parameters
•Measurement
•Options
•Special functions
The program branch is displayed between 2 arrows ( ).
Fig. 4.1: Example of a measurement arrangement
1 – transducer pair A
2 – transducer pair B
3 – pipe
4 – transmitter
Fig. 4.2: Command panel of the transmitter
1 – LCD display (backlit)
2 – keyboard
1
3
4
2
A B
A B
ENTER
CH BCH A
BRKCLR
Ulrasonic Flowmeter
2
1

4 Product description
4.2 Handling concept FLUXUS G831ST-HT
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When starting up the transmitter for the first time, settings relating to the language, time, date and system of units have to
be made. Then the program branch Parameters will be displayed.
At later start-ups the measured values will be displayed in case the measurement had not been stopped before the
transmitter was disconnected from the power supply. If the measurement had been stopped, the program branch
Parameters will be displayed.
After starting the measurement, the parameter settings or the configuration of the transmitter outputs can be displayed at
any time without interrupting the measurement. A change of the parameter settings is not possible during the
measurement. The measurement has to be stopped in order to change the parameter settings or configuration of the
transmitter outputs.
Tab. 4.1: Description of the program branches
Program branch Description
Parameters Before starting a measurement, the transducer, pipe and fluid parameters have to be entered in the
program branch Parameters.
Measurement Having entered the parameters for the measuring point, the measurement can be started in the
program branch Measurement.
Options Settings are carried out in the program branch Options, e.g., selection of the physical quantity and
unit of measurement, input of the damping factor, configuration of the outputs, assignation of the
inputs.
Special functions Global settings relating to the transmitter are carried out in the program branch Special
functions, e.g., system settings (language, key lock), measurement settings, communication, data
logger, snaps, configuration of inputs.

4 Product description
FLUXUS G831ST-HT 4.3 Display
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4.3 Display
Structure
Status indications
Several symbols are used for the status indications.
Fig. 4.3: Menu item of the program branch Parameters
1 – program branch
2 – currently edited menu item
3 – area for scroll lists, selection fields or input fields
Tab. 4.2: Navigation
horizontal scroll list vertical scroll list input fields
• scroll horizontally with or
CLR
• scroll vertically with or • input numbers or text with
or
• delete with C
Fig. 4.4: Status indications (line 1)
1
2
3
error message
running measurement
data logger full
key lock activated
connection via USB cable

4 Product description
4.4 Keyboard FLUXUS G831ST-HT
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4.4 Keyboard
The keyboard consists of the following keys: ENTER, BRK, CLR, and . The keys are operated using a magnetic
pen with the housing being closed.
Tab. 4.3: General functions
ENTER confirmation of selection or input
BRK during the parameter input:
short press: return to the previous menu item
long press (several seconds): return to the beginning of the program branch
during the measurement:
display of scroll list: Stop measurement, Show parameters, Show measurement
Tab. 4.4: Navigation
scroll to the right or up through a scroll list
scroll down through a scroll list
CLR scroll to the left through a scroll list
Tab. 4.5: Input of numbers
move the cursor to the right
scroll through the numbers above the cursor
CLR short press: move the cursor to the left
long press (several seconds): reset the value to the previously stored one
Tab. 4.6: Input of text
move the cursor to the right
scroll through the characters above the cursor
CLR short press: move the cursor to the left
long press (several seconds): reset the text to the previously stored one