MATHMET

The European Centre for
Mathematics and Statistics in Metrology

EMPIR 14SIP08
“Standards and software to maximise end user uptake of NMI calibrations of dynamic force, torque and pressure sensors“

Description

Involved MATHMET members
NPL (UK), PTB (Germany)
Project partners
HBM GmbH (Germany), Rolls Royce plc (UK)
Duration
05/2015 - 04/2018
Website
PyDynamic source code: github.com/eichstaedtPTB/PyDynamic
PyDynamic documentation: pydynamic.readthedocs.io
Overview

The aim of this project is to maximise uptake by industry end users and the Joint Committee for Guides in Metrology (JCGM) of outputs of EMRP JRP IND09 (Traceable dynamic measurement of mechanical quantities) by providing concrete, specific and directed advice on how to make best use of the results of dynamic calibrations provided by NMIs.

Need

Many applications of the measurement of quantities such as force, torque and pressure are dynamic, i.e. the measurand shows a strong variation over time. Transducers are in most cases calibrated by static procedures owing to a lack of commonly accepted procedures or documentary standards for the dynamic calibration of mechanical sensors. However, it is well known that mechanical sensors exhibit distinctive dynamic behaviour that shows an increasing deviation from static sensitivity characteristics as frequency increases. This lack of dynamic calibration standards also applies to the electrical conditioning components of the measurement chain

Previously, JRP IND09 sought to establish metrological traceability for the mechanical quantities; dynamic force, torque and pressure. The key output of JRP IND09 was the establishment of primary and secondary NMI-level traceability for the mechanical quantities; dynamic force, dynamic torque and dynamic pressure. However effective dissemination of dynamic calibrations requires specific advice to be provided to industrial end users on how to use calibration results to correct measurements for dynamic effects and to demonstrate compliance with the Guide to the expression of uncertainty in measurement (GUM). Although JRP IND09 (i) developed general dynamic models for the complete calibration measurement chain, (ii) developed procedures for uncertainty evaluation in line with uncertainty evaluation for static measurements, and (iii) established general procedures for correcting measurements for dynamic effects, these were not able to be embodied in documentary standards and international guidance documents or in software that can be used in industrial applications to correct measurements and provide GUM-compliant uncertainty evaluations, during the lifetime of the project.

Calibration certificates and associated information provided for dynamic quantities by NMIs and accredited calibration laboratories can take several forms, such as parameterised models of the sensors and measuring systems that are calibrated, or frequency response data that describes the amplitude and phase response of the calibrated system as a function of frequency. In addition, sensors alone may be calibrated, so that the end user has to understand how the remainder of the measuring system (amplifiers, filters, digital acquisition systems) affects the performance of the calibrated system. The calibration methods may also be based on a variety of input signals, sine waves, chirps, steps and impulses, and the choice of signal determines what calibration information may be obtainable and how it may be used. Therefore, industrial end users require (i) guidance on what calibration information to request from NMIs and accredited calibration laboratories, (ii) guidance on how to use this information in their own dynamic measurement applications to ensure compliance with the GUM, and (iii) software that demonstrates the guidance in action.

Objectives

The specific technical objectives of this project are concerned with providing detailed practical guidance in measurement uncertainty evaluation for industrial end users of the outputs from JRP IND09:
1. To provide written advice and guidance to end users, that demonstrates (by means of case studies applied to end user data) methods to evaluate reliable estimates of dynamic mechanical quantities and their associated uncertainties, taking into account the various forms that calibration results may take as well as correlation effects.
2. To make publicly available, validated and tested software for industrial end users to implement the methods described in point 1 above.
These activities align directly with identified end user needs, who require specific guidance on how to apply the outputs of JRP IND09; to their own measurements of dynamic effects in engines and to their selection of suitable sensors so as to establish confidence in their measurement results; to be able to show that they comply with best practice in uncertainty evaluation in accordance with the GUM; and to understand how the deconvolution and correction algorithms needed for this purpose can be embodied in validated software..

Impact

Direct impact will be achieved by this project by ensuring the widest possible uptake of the outputs of the mathematics and statistics work from JRP IND09. This will be done by via a scientific paper, a contribution to a suitable trade journal and a written contribution to JCGM Documents 103 and Document 110, which demonstrate the methods developed in JRP IND09 in action, on typical end user data provided by key industrial stakeholders.
The project will also create impact by enabling efficient application of the methods developed in JRP IND09 by disseminating software, that demonstrate the methods in action on industrially relevant example data, to industry end users and through the public websites of NPL and PTB.
Stacks Image 231758
Overview

The aim of this project is to maximise uptake by industry end users and the Joint Committee for Guides in Metrology (JCGM) of outputs of EMRP JRP IND09 (Traceable dynamic measurement of mechanical quantities) by providing concrete, specific and directed advice on how to make best use of the results of dynamic calibrations provided by NMIs.

Need

Many applications of the measurement of quantities such as force, torque and pressure are dynamic, i.e. the measurand shows a strong variation over time. Transducers are in most cases calibrated by static procedures owing to a lack of commonly accepted procedures or documentary standards for the dynamic calibration of mechanical sensors. However, it is well known that mechanical sensors exhibit distinctive dynamic behaviour that shows an increasing deviation from static sensitivity characteristics as frequency increases. This lack of dynamic calibration standards also applies to the electrical conditioning components of the measurement chain

Previously, JRP IND09 sought to establish metrological traceability for the mechanical quantities; dynamic force, torque and pressure. The key output of JRP IND09 was the establishment of primary and secondary NMI-level traceability for the mechanical quantities; dynamic force, dynamic torque and dynamic pressure. However effective dissemination of dynamic calibrations requires specific advice to be provided to industrial end users on how to use calibration results to correct measurements for dynamic effects and to demonstrate compliance with the Guide to the expression of uncertainty in measurement (GUM). Although JRP IND09 (i) developed general dynamic models for the complete calibration measurement chain, (ii) developed procedures for uncertainty evaluation in line with uncertainty evaluation for static measurements, and (iii) established general procedures for correcting measurements for dynamic effects, these were not able to be embodied in documentary standards and international guidance documents or in software that can be used in industrial applications to correct measurements and provide GUM-compliant uncertainty evaluations, during the lifetime of the project.

Calibration certificates and associated information provided for dynamic quantities by NMIs and accredited calibration laboratories can take several forms, such as parameterised models of the sensors and measuring systems that are calibrated, or frequency response data that describes the amplitude and phase response of the calibrated system as a function of frequency. In addition, sensors alone may be calibrated, so that the end user has to understand how the remainder of the measuring system (amplifiers, filters, digital acquisition systems) affects the performance of the calibrated system. The calibration methods may also be based on a variety of input signals, sine waves, chirps, steps and impulses, and the choice of signal determines what calibration information may be obtainable and how it may be used. Therefore, industrial end users require (i) guidance on what calibration information to request from NMIs and accredited calibration laboratories, (ii) guidance on how to use this information in their own dynamic measurement applications to ensure compliance with the GUM, and (iii) software that demonstrates the guidance in action.

Objectives

The specific technical objectives of this project are concerned with providing detailed practical guidance in measurement uncertainty evaluation for industrial end users of the outputs from JRP IND09:
1. To provide written advice and guidance to end users, that demonstrates (by means of case studies applied to end user data) methods to evaluate reliable estimates of dynamic mechanical quantities and their associated uncertainties, taking into account the various forms that calibration results may take as well as correlation effects.
2. To make publicly available, validated and tested software for industrial end users to implement the methods described in point 1 above.
These activities align directly with identified end user needs, who require specific guidance on how to apply the outputs of JRP IND09; to their own measurements of dynamic effects in engines and to their selection of suitable sensors so as to establish confidence in their measurement results; to be able to show that they comply with best practice in uncertainty evaluation in accordance with the GUM; and to understand how the deconvolution and correction algorithms needed for this purpose can be embodied in validated software..

Impact

Direct impact will be achieved by this project by ensuring the widest possible uptake of the outputs of the mathematics and statistics work from JRP IND09. This will be done by via a scientific paper, a contribution to a suitable trade journal and a written contribution to JCGM Documents 103 and Document 110, which demonstrate the methods developed in JRP IND09 in action, on typical end user data provided by key industrial stakeholders.
The project will also create impact by enabling efficient application of the methods developed in JRP IND09 by disseminating software, that demonstrate the methods in action on industrially relevant example data, to industry end users and through the public websites of NPL and PTB.

Publications

Twitter feed of @PyDynamic

Related conference presentations

Authors
Title
Journal
Year
S. Eichstädt, T. J. Esward and A. SchäferOn the necessity of dynamic calibration for improved traceability of mechanical quantitiesXXI IMEKO World Congress, Prague, Czech Republic2015

Related scientific publications

Stacks Image 9788
This work is part of the European Metrology Programme for Innovation and Research (EMPIR) project 14SIP08. The EMPIR is jointly funded by the EMPIR participating countries within EURAMET and the European Union.
More information can be found here.
x
This website uses cookies occasionally to provide you with the best web browsing experience. However, no web-analytics tracking based on cookies is employed here.