Yokogawa digitalYEWFLO (DY) - Manual (Page 3)

TABLE OF CONTENTS
IM 1F2B4-01-YIA
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IV. MAINTENANCE ...................................................................................................... 58
4.1
How to ........................................................................................................... 58
4.1.1
Communicating with the YEWFLO remotely ..................................... 59
4.1.2 Adjusting zero and span ..................................................................... 60
4.1.3 Using self-diagnostics ........................................................................ 61
4.1.4 Simulating an output/performing a loop check .................................... 62
4.1.5 Changing the output mode to analog or pulse ..................................... 63
4.1.6 Increasing gas and steam flow measurement accuracy by correcting
for gas expansion ............................................................................... 64
4.1.7 Activating Reynolds number correction .............................................. 65
4.1.8 Activating mismatched pipe schedule (bore) correction ...................... 66
4.1.9 Setting up and resetting the internal totalizer ...................................... 67
4.1.10 Scaling the pulse output ..................................................................... 68
4.1.11 Setting up user defined flow units ...................................................... 69
4.1.12 Setting up the local LCD indicator display mode ................................ 70
4.1.13 Setting the low cut flowrate ................................................................ 71
4.1.14 Trimming the 4-20 mA analog output ................................................. 72
4.1.15 Using the upload/download feature .................................................... 74
4.2 Disassembly and Reassembly .......................................................................... 75
4.2.1
Indicator/Totalizer removal ................................................................ 75
4.2.2 Amplifier replacement ........................................................................ 75
4.3 Vortex Shedder Assembly Removal ................................................................ 76
4.3.1
Removal of shedder from remote converter type ................................. 76
4.3.2 Removal of the shedder from integral type ......................................... 77
4.4 Reassembly Cautions ...................................................................................... 78
4.4.1
YEWFLO shedder bolt torque procedures .......................................... 78
4.5 YEWFLO Style "E" Amplifier Calibration Procedure ..................................... 81
4.5.1
General amplifier checkout ................................................................ 82
4.5.2 Analog output test .............................................................................. 82
4.5.3 Pulse output test ................................................................................. 83
V. PARAMETER SETTING/CONFIGURATION ....................................................... 84
5.1
Notes on the TBL optional digital display ....................................................... 84
5.1.1
Display contents in display section ..................................................... 85
VI. TROUBLESHOOTING ............................................................................................ 88
6.1
Error Code Listing .......................................................................................... 88
6.2 Operating Procedures ...................................................................................... 89
6.3 Flow Computation .......................................................................................... 92
6.3.1
Variable definitions ............................................................................ 92
6.3.2 Flow conversion factor ....................................................................... 93
6.4 Signal Conditioning ........................................................................................ 94
6.4.1
YEWFLO Style "E" signal adjustment procedure ............................... 94
6.4.2 Problem solving ................................................................................. 94
6.4.3 Piping checkout procedure ................................................................. 94
6.4.4 Noise balance adjustment ................................................................... 95
6.4.5 Noise judge ........................................................................................ 96
6.4.6 TLA adjustment ................................................................................. 96
6.4.7 Low-cut flowrate adjustment .............................................................. 97
6.4.8 High-frequency filter adjustment ........................................................ 97
6.5 Flowcharts ...................................................................................................... 98
6.5.1
No flowmeter output under flowing conditions ................................... 98
6.5.2 Flowmeter output with no flow ......................................................... 100
6.5.3 Large flowmeter errors ..................................................................... 101
6.5.4 Output is unstable when flowrate is low ........................................... 102