ISO 20083-3-2019 PDF

Full title and description

Ships and marine technology — Determination of the shaft power of ship propulsion systems by measuring the shaft distortion — Part 3: Elastic vibration method. This international standard specifies a procedure for determining shaft power on ships by measuring torsional (shaft) distortion using an elastic‑vibration type shaft power meter; it defines measurement principles, device components, calculation methods, accuracy factors and the required on‑board documentation for the device.

Abstract

ISO 20083-3:2019 describes the elastic vibration method for measuring shaft distortion to derive shaft torque and shaft power of ship propulsion systems. The document covers the physical/measurement principle, the main elements of the elastic‑vibration sensor assembly and associated peripherals, the mathematical relationship and calculation steps to convert measured torsional deformation and rpm into shaft torque and power, and guidance on factors that influence measurement accuracy and on the documentation that must accompany the device on board.

General information

• Status: Published (confirmed after periodic review).
• Publication date: June 2019 (published 5 June 2019; confirmed in 2024).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 47.020.20 (Marine engines and propulsion systems).
• Edition / version: Edition 1 (2019).
• Number of pages: 8 (ISO edition).

Scope

The standard specifies a measurement procedure for determining shaft power of engine ships by measuring shaft distortion using an elastic‑vibration type device. It is intended to provide a repeatable method for field measurement of shaft torque and power without direct coupling to the propulsion shafting system. The document defines the measurement principle, required device components and installation considerations, calculation and compensation methods, factors affecting accuracy (and their treatment) and the minimum on‑board documentation to support correct use, calibration and interpretation of results.

Key topics and requirements

• Measurement principle: deriving torque from torsional (elastic) vibration/shaft distortion combined with shaft rotational speed to compute shaft power.
• Device components: elastic vibration sensor assembly (split rings or mounted elements), excitation and pickup units, non‑contact transmitting/receiving elements and data acquisition/processing peripherals.
• Calculation method: formulas and processing steps to convert measured torsional deformation and rpm into torque and shaft power, including necessary constants and conversions.
• Calibration and sensitivity: requirement for device calibration, individual sensor sensitivity constants and zero‑point procedures to ensure traceable results.
• Accuracy influences and corrections: environmental and mechanical factors (shaft material and geometry, temperature, mounting/alignment, sensor behaviour) that affect measurement uncertainty and how to account for them.
• On‑board documentation: minimum content for manuals, calibration records, installation instructions and routine check procedures to be carried with the device.

Typical use and users

Used by shipbuilders, shipyards, marine surveyors, classification societies, marine engineers, on‑board technical staff and test laboratories for commissioning, performance verification, sea trials and diagnostics of propulsion systems. Also used by manufacturers and suppliers of shaft power meters and by organisations performing fuel efficiency and emissions-related measurements where accurate shaft power data are required.

Related standards

ISO 20083 is published as a multipart series covering different measurement methods. Closely related items include ISO 20083-2:2019 (Part 2 — Optical reflection method) and national/adopted versions (for example BS ISO 20083-3:2019). The standard is developed under ISO/TC 8/SC 2 (ships and marine technology) and should be used alongside other marine measurement, calibration and uncertainty standards appropriate to the measurement task.

Keywords

shaft power; shaft distortion; torsional vibration; elastic vibration method; torque measurement; ship propulsion; shaft power meter; marine engineering; ISO 20083; ISO/TC 8/SC 2.

FAQ

Q: What is this standard?

A: ISO 20083-3:2019 is an international standard that specifies the elastic‑vibration method for measuring shaft distortion to determine shaft torque and shaft power of ship propulsion systems.

Q: What does it cover?

A: It covers the measurement principle, the components and installation of an elastic‑vibration type shaft power meter, the calculation method to convert measured distortion and rpm into torque and power, factors affecting measurement accuracy and the required on‑board documentation.

Q: Who typically uses it?

A: Shipbuilders, marine engineers, test laboratories, classification societies, suppliers of shaft power measurement equipment, and on‑board technical staff responsible for commissioning, trials and performance verification.

Q: Is it current or superseded?

A: This edition was published in June 2019 and was confirmed in a subsequent periodic review; it is the current published version (Edition 1, 2019) at the time of confirmation.

Q: Is it part of a series?

A: Yes — ISO 20083 is a multipart series addressing shaft power determination by shaft distortion measurement. Part 2 (ISO 20083-2:2019) covers an optical reflection method; Part 3 covers the elastic vibration method.

Q: What are the key keywords?

A: shaft power, shaft distortion, torsional vibration, elastic vibration, torque measurement, ship propulsion, shaft power meter, marine measurement.