ISO 19636:2019

INTERNATIONAL ISO
STANDARD 19636
First edition
2019-02
Ships and marine technology —
General requirements for
inclinometers used for the
determination of trim and list of LNG
carriers
Navires et technologie maritime — Exigences générales relatives aux
inclinomètres utilisés pour la détermination de l'assiette et liste des
méthaniers
Reference number
©
ISO 2019
© ISO 2019
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ii © ISO 2019 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Safety precautions . 2
4.1 Existing safety regulations, standards and classification societies rules . 2
4.2 Equipment precautions . 2
5 Design requirements . 3
5.1 General . 3
5.2 A Trim and list inclinometer’s axes and range . 3
5.3 Communication methods . 3
5.3.1 Analogue current interface type . 3
5.3.2 Digital interface type . 3
5.4 Levelling of a trim and list inclinometer . 3
5.5 A trim and list inclinometer’s protection box . 4
5.6 Sealing, security and unsealing . 4
5.7 Marking serial number . 4
6 Installation . 5
6.1 General . 5
6.2 Installation of a trim and list inclinometer . 5
6.3 Alignment of a trim and list inclinometer . 5
6.4 Alignment of a trim and list inclinometer — Ship at dry dock . 6
6.5 Installation of a trim and list inclinometer — Ship at floating dock . 6
6.6 Installation of a trim and list inclinometer — Ship anchored or moored . 7
7 Accuracy . 8
7.1 General . 8
7.2 Uncertainty of a Trim and List inclinometer's inherent error - Factory acceptance
test (FAT) . 8
7.3 Uncertainty of reference standard -Site acceptance test (SAT) . 8
7.4 Integrated overall accuracy . 9
8 Verification test and certification . 9
8.1 General . 9
8.2 Visual examination . 9
8.3 Verification test . .10
8.4 Sealing .10
8.5 Certificate .10
Annex A (informative) Verification of alignment for trim and list inclinometers .11
Bibliography .13
Foreword
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This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology,
Subcommittee SC 8, Ship design.
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iv © ISO 2019 – All rights reserved

Introduction
Inclinometers are used to determine the trim and list of various types of ships floating on the water.
In the case of liquefied natural gas carriers (LNG carriers), on which a large quantity of LNG is traded,
based on the results of static measurement, determination of trim and list, along with other elements, is
particularly important because the measurement of the liquid level of a cargo tank is inevitably affected
by the ship’s inclination.
This document provides general requirements for the accuracy, installation, calibration and
verification of inclinometers used for the determination of trim and list of LNG carriers, but is not
intended to preclude the use or development of any other technologies or methods or the revision of
the methods presented. Users of this document are encouraged to review, in detail, the latest editions
of the publications, standards and documents referenced in this document in order to gain a better
understanding of the methods described.
Users of this document should consider the applicable safety or operating practices recommended by
organizations, such as the International Maritime Organization (IMO), the International Chamber of
Shipping (ICS), the Oil Companies International Marine Forum (OCIMF), the International Group of
LNG Importers (GIIGNL) and the Society of International Gas Tanker and Terminal Operators (SIGTTO),
or individual operating companies, as well as any other safety or environmental considerations, local
regulations or the specific provisions of any contract.
INTERNATIONAL STANDARD ISO 19636:2019(E)
Ships and marine technology — General requirements for
inclinometers used for the determination of trim and list of
LNG carriers
1 Scope
This document provides general requirements for the accuracy, installation, calibration and verification
of trim and list inclinometers used for the determination of trim and list of LNG carriers for the purpose
of measuring on-board cargo level.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60079-0, Explosive atmospheres —Part 0: Equipment — General requirements
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
custody transfer measurement system
CTMS
system that processes inputs from an ATG (automatic tank gauge) system, thermometers, pressure
gauges, etc., and provides custody transfer measurement information on board, generating documents
with regard to custody transfer of LNG
Note 1 to entry: CTMS components include:
a) automatic level gauge system (radar, microwave, capacitance and float types),
b) automatic temperature gauge,
c) automatic pressure gauge,
d) trim and list indication system
Note 2 to entry: A trim and List inclinometer system can be typically incorporated as part of a CTMS.
Note 3 to entry: See Figure 1.
Key
1 trim and list inclinometer 4 connection/control box
2 sensor 5 custody transfer system (cts) unit
3 protection box 6 trim and list indicator
Figure 1 — Outline of trim and list inclinometer system
3.2
trim and list inclinometer
inclinometer used to determine the trim and list of LNG carriers
3.3
inherent error
error of a trim and list inclinometer when it is tested and verified against a re
...