Delta-T SWT4, User Manual

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SWT4 User Manual v3.1
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Table of contents
User Manual for the 1
Tensiometer 1
Notices 2
1 Introduction 5
1.1 Safety instructions and warnings 5
1.2 Unpacking 6
1.3 Foreword 6
1.4 Guarantee 6
1.5 Durability 6
1.6 SWT4 and SWT4R 7
1.6.1 Soils and soil water 7
1.6.2 Intended use 7
1.6.3 Types 7
1.7 Quick Start 8
2 Sensor Description 12
2.1 Parts 12
2.1.1 Body and shaft 12
2.1.2 Pressure sensor 12
2.1.3 Reference air pressure 12
2.1.4 The ceramic cup 13
2.2 External refilling (SWT4R only) 13
2.3 Analog output signals 14
3 Installation 15
3.1 Advance planning 15
3.1.1 Selecting the measuring site 15
3.1.2 Number of Tensiometers per level 15
3.1.3 Extent of the site 15
3.1.4 Protection of refilling tubes (SWT4R only) 16
3.1.5 Use of Tube Jackets and Conduit 16
3.1.6 Ideal conditions for installation 17
3.1.7 Documentation 17
3.2 Selecting the installation angle 18
3.2.1 "Vertical" tilting downwards (SWT4R only) 18
3.2.2 "Horizontal" tilting upwards (SWT4R only) 18
3.3 Installation procedure 19
3.4 Offset correction for non horizontal installations 21
3.4.1 How to measure the zero offset of a tilted tensiometer 22
3.5 Connecting SWT4 and SWT4R 23
3.5.1 Spot reading with the SWT-MR (Infield7) 23
3.5.2 Connecting cables 23
3.5.3 Connection to a data logger 23
3.5.4 Connection to Delta-T Loggers 24
4 Service and maintenance 26