Content
Overview
Dynamic measurements can be found in many areas of metrology and industry such as, for instance, in the measurement of time-dependent forces or accelerations. Methods from signal processing are often applied in the analysis of dynamic measurements. In many applications linear time-invariant systems are appropriate to model dynamic measurements, where the output signal is obtained as a convolution of the input signal and the measurement system’s impulse response. Input and output signal are not proportional to each other, and estimation of the system’s input signal from its output signal constitutes one important task in the analysis of dynamic measurements. Often digital filters are employed for this purpose. The evaluation of the uncertainty associated with the estimated input signal is particularly important from a metrological perspective.
Typical examples are measurements of mechanical quantities as, for example, force, torque and pressure. Further examples are oscilloscope measurements for the characterization of high speed electronics, hydrophone measurements for the characterization of medical ultrasound devices, the spectral characterization of radiation sources, spectral color measurements and camera-aided temperature measurements.
Research
One focus of PTB‘s Working Group 8.42 is the development of methods for the estimation of the input signal from the output signal when the dynamic behavior of the measurement system has been characterized. This includes the development of procedures for the evaluation of the uncertainty associated with the estimated input signal. Another focus is the development of methods for the analysis of dynamic calibration measurements aimed at determining the dynamic behavior of a measurement system.
Software
Publications
Publication single view
Article
| Title: | Evaluation of measurement uncertainties for time-dependent quantities |
|---|---|
| Author(s): | S. Eichstädt, B. Arendacká, A. Link and C. Elster |
| Journal: | EPJ Web of Conferences |
| Year: | 2014 |
| Book title: | EPJ Web of Conferences |
| Volume: | 77 |
| Issue: | 3 |
| DOI: | 10.1051/epjconf/20147700003 |
| File URL: | fileadmin/internet/fachabteilungen/abteilung_8/8.4_mathematische_modellierung/Publikationen_8.4/epjconf_icm2014_00003.pdf |
| Tags: | 8.42, Dynamik |
| Abstract: | One of the main challenges in the analysis of dynamic measurements is the estimation of the time-dependent value of the measurand and the corresponding propagation of uncertainties. In this paper we outline the design of appropriate digital compensation filters as a means of estimating the quantity of interest. For the propagation of uncertainty in the application of such digital filters we present online formulae for finite impulse response and infinite impulse response filters. We also demonstrate a recently developed efficient Monte Carlo method for uncertainty propagation in dynamic measurements which allows calculating point-wise coverage intervals in real-time. |