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J. Nitsche, D. Röske, R. Tutsch
Influence of Coordinate System Alignment on the Calibration of Multi-Component Force and Moment Sensors

For the calibration of multi-component force and moment sensors no national or international standard exists. In different approaches for calibration procedures, a precise alignment of sensor and calibration reference is required. The influence of such an alignment, however, is not mentioned.
Based on a model of a calibration setup and an assumption of possible misalignments, an analysis of the systematic error, caused by such misalignment, is performed. Additionally, a strategy to identify the necessary coordinate transformation is given.

M. Grum, G. Grgic
Test Load Reference Mass Value for AWI Calibration

Calibration of automatic weighing instruments in a dynamic mode of operation can not be performed directly with standard weights. It is necessary to use products or items that are normally weighed on these instruments. Several approaches are presented and discussed in the article for determination of the reference mass value of the test loads used for the calibration of automatic weighing instruments. For each presented approach uncertainty components are identified and evaluated. Finally, the indicative classification of presented methods with regard to their accuracy is carried out.

Ángel Lumbreras, Jose Luis Ocaña , Héctor Fuentes, Javier Gamarra, Dolores de la Piedra, Nieves Medina
Study of the Effect of Laser Marking for Standard Weights

Most class E weights are made of austenitic stainless steel and they do not have any marking to be distinguished. In this study two special types of laser marking have been used to provide a proper marking so that the marking effect is negligible for the mass value and the corresponding drift. The drift has been studied by means of several calibrations during more than 10 years.

F. Crößmann
Investigation of the Calibration Capabilities of a 1 kN·m And 10 kN·m Reference Calibration Machine

To expand the capacity of its calibration laboratory, Hottinger Baldwin Messtechnik GmbH is planning to use two new reference calibration machines in the range up to 1 kN·m and 10 kN·m respectively. In addition to the theoretical consideration of the individual elements contributing to measurement uncertainty, measurement data is also compared using the En value as a demonstration of the target measurement uncertainty of 0,02% (k = 2).

Tao Li, Hongli Qi, Xidong Ni, Yi Chen, Yaowu Wang
The Realization of Micro-Torque Calibration and Measurement Device

The calibration and measurement of micro-torque have long been the research focus of inertial navigation system. In this paper, the micro-torque calibration and measurement device based on knife-edge support are proposed, which combine the electromagnetic force balance and indifferent equilibrium technology to realize selfish calibration and automatic measurement. This device can be used to measure 10-5 N·m torque of components of inertial navigation system. This paper aims to describe the basic theory and critical techniques. Uncertainty is evaluated and experiments were done to evaluate the repeatability of the device. The work is standing out in the field of international torque calibration.

Falk Tegtmeier, Dirk Röske, Wei Liang
Practical Applications of an Enhanced Uncertainty Model for Build-Up Systems

This paper describes the development of a new uncertainty model for build-up systems (BU systems) within the scope of the EMRP SIB 63 project, which deals with transfer standards in the meganewton range. The paper, in general, describes an optimized way of lowering uncertainties when using BU systems. We present the results of our investigation on how to optimize mechanical design for such systems, as well as a measurement procedure and a derived uncertainty model. Finally, the usefulness of this theory is demonstrated in three practical applications at NPL (London, UK), at the MPA (Braunschweig, Germany) and at FJIM (Fuzhou, China).

Leonard Klaus, M. Florian Beug, Thomas Bruns
A New Calibration Set-Up for the Dynamic Calibration of Bridge Amplifiers from DC up to 10 kHz

Measurements of mechanical quantities are often carried out with transducers having a bridge output. These output signals are conditioned using bridge amplifiers. If dynamically changing quantities are going to be measured traceably, the bridge amplifier has to be calibrated dynamically.
This paper describes a dynamic bridge amplifier calibration set-up based on the new PTB dynamic bridge standard. The calibration is carried out by synchronous sampling of the bridge amplifier output voltage and a reference signal provided by the calibrated dynamic bridge standard. The dynamic bridge standard enables calibrations in a frequency range from DC (static calibration) up to 10 kHz. An overview of the different measurement uncertainty contributions is given and first measurement results show a good agreement with a previously established measurement set-up.

G. Foyer, S. Kock
Measurement Uncertainty Evaluation of Torque Measurements in Nacelle Test Benches

Torque measurement in the MN·m range is important in nacelle test benches, as it constitutes a main value for the efficiency determination of wind turbine drive trains. However, no traceable measurement is possible above 1.1 MN·m. At the moment, alternatives to direct torque measurement in the MN·m range are, therefore, used. Several of these torque measurement methods are presented and discussed in this paper with respect to traceability and measurement uncertainty. As these methods cannot substitute direct measurements fully, recommendations for a calibration procedure are given to enable a calibration of torque measurement using a torque transfer standard.

Gang Hu, Jile Jiang, Tao Li, Zhimin Zhang, Honglei Ji, Lijun Zhuang National
A New 10 N Deadweight Force Standard Machine

A new 10N deadweight force standard machine is developed by NIM. The force range of this machine is from 1mN to 10N. There are 10 groups of weights, 10 pieces deadweights in each group. This machine is composed of deadweights, automatic loading and unloading system, load frame and deadweight hanging system, balance mechanism and so on. Air bearing technique is applied to the balance mechanism. The structure of the deadweight force standard and its main components are introduced in detail. The performance test results of the air bearing are demonstrated in this paper.

Klaus Fritsch
EURAMET cg-18 - Calibration of Balances and Scales - Update on International Distribution and Acceptance

This paper presents the state-of-the-art calibration strategy for non-automatic weighing instruments (NAWI), based on the recently revised guideline EURAMET cg-18. Besides of the uncertainty at calibration, the document provides advice for the so-called uncertainty of a weighing result that describes the device performance during day-to-day use. The concept of minimum weight was added during a recent revision. The minimum weight is the smallest sample quantity that can be weighed on the device, still adhering to a predefined relative weighing tolerance requirement.

Page 305 of 977 Results 3041 - 3050 of 9762