## IMEKO Event Proceedings Search

Page 9 of 891 Results 81 - 90 of 8905

**A NOVEL EMFC TILTMETER WITH EXTENDED MEASUREMENT RANGE**

This work presents a new tiltmeter that utilises the principle of electromagnetic force compensation (EMFC) in order to increase its measurement range and measurement dynamics compared to an uncompensated pendulum tiltmeter. The development included investigations on the design of the pendulum mechanics, the position sensor and the actuators. With the chosen parameters a resolution of 1 µrad in a measurement range of 20 mrad can be achieved currently on a short-term timescale.

**THE DEVELOPMENT OF DEADWEIGHT FORCE STANDARD MACHINE OF 500 kN WITH WEIGHT EXCHANGE CONTROL SYSTEM**

Based on the “force standard machine weights exchange method and weights exchange device” patent technology, a deadweight force standard machine (DWM) of 500 kN was developed. Benefited by the weights exchange control system with eight weights and load frame，this machine can load/unload any load level equally with the minimum increment of 10 kN, in 10 kN to 500 kN range，and the load history curve is basically the same. Eliminating the counter-force phenomenon in traditional DWM, it meets the technical requirements of OIML R 60 international recommendations for loading equipment.

**TRANSDUCER RESPONSE UNDER NON-STANDARDISED TORQUE LOAD PROFILES**

In nacelle system test benches, different wind profiles are simulated by applying different torque loads and rotational speeds amongst other things. Unlike load sequences during calibration measurements, these profiles are neither constant nor increasing and decreasing through controlled steps. This article proposes a sequence of partial range and shuffled torque load tests that combine torque rates and filter settings to evaluate parameters affecting the measurement results, such as output sensitivity, linearity, and hysteresis.

**CAPACITIVE CALIBRATION CAPABILITIES IN AN EMFC BALANCE**

The article describes the possibilities of calibrating the force constant in an electromagnetic force compensation (EMFC) load cell using the electrostatic force compensation principle. The static and dynamic principles of calibration of the Kibble balance for the electrostatic force constant, as well as calibration by means of compensation of the electrostatic force by the electromagnetic force, are considered. The combination of the two compensation principles in the load cell allows the measurement of forces in the range of 20 pN to 2.2 mN and ensures traceability to national standards. The relative uncertainty in the measurement of forces of about 100 nN is estimated to be about 0.001.

**RESEARCH ON TEST METHOD OF ABNORMAL PASS BEHAVIOUR OFAUTOMATIC INSTRUMENTS FOR WEIGHING ROAD VEHICLES IN MOTION**

This paper introduces common abnormal pass behaviour of automatic instruments for weighing road vehicles in motion (WIM) and gives the corresponding test method. Common abnormal behaviour of WIM includes “S-line” driving, “static and dynamic” driving, “line pressing” driving, and “cross road” driving.

**GUIDE TO THE CALIBRATION OF HYDRAULIC TORQUE WRENCHES**

This paper describes the new proposal of the calibration of hydraulic torque wrenches. The calibration includes the different metrological effects of the hydraulic torque wrenches like repeatability, reproducibility, and the piston position. A sensitivity analysis is introduced to the different uncertainty contributions of the of hydraulic torque wrenches like the piston position, mounting position and the mechanical adaptation. The measurements show that the piston position has the significant influence on the measurement uncertainty of the calibration result. The uncertainty evaluation of the calibration facility is introduced including the effect of the lateral forces that comes from the application of relatively high torque values with short lever arm lengths. The estimation of the measurement results and the corresponding uncertainty are performed like the calibration standard ISO DIN 51309 without the estimation of the hysteresis. The calibration method and the corresponding validation are accepted from the German DAkkS accreditation body.

**DEVELOPING A KIBBLE BALANCE FOR MEASURING ULTRASONIC RADIATION FORCE AT 1 MEGAHERTZ**

Various approaches to bench-top Kibble balances are available worldwide. However, the literature has not disclosed a Kibble balance to measure ultrasonic radiation force (URF). Due to the nature of Kibble balances, assessing URF could be useful and even more valuable. This paper describes the development of a bench-top Kibble balance to measure URF. The system was compared to the Brazilian National Metrology Institute's primary standard for ultrasonic power measurement. Regarding the regular microbalance used for that purpose, the Kibble balance approach led to a smaller uncertainty in the 10 W to 20 W range.

**EXPERIMENTAL RESULTS OF MEASUREMENT HINGE FLEXURE STIFFNESS DETERMINATION**

A hinge measurement flexure calibration set-up for stiffness measurements has been built at the Physikalisch-Technische Bundesanstalt (PTB) to estimate parasitic loads on PTB’s 5 MN·m torque standard machine (TSM). This paper describes the improvements made to a measurement flexure calibration set-up made since its first presentation. The list of measurement uncertainty influences is refined. Initial results of a combined transversal force and bending and torque moment stiffness measurement are presented and compared to a previous finite element analysis.

**INFLUENCE OF PARASITIC COMPONENTS IN THE STATIC CALIBRATION OF UNIAXIAL FORCE TRANSDUCERS**

Static calibration of uniaxial force transducers is performed with force standard machines which ideally generate a downward vertical force. However, these machines can be subjected to parasitic components, such as side forces and bending moments, which are transferred to the transducer under calibration. These components, mainly due to the not perfect verticality or alignment of the applied force, affect the calibration results, thus they should be estimated. In this work, parasitic side forces and bending moments are applied to six transducers by tilting and misaligning them with respect to the vertical gravitational force. Sensitivity coefficients of these parasitic components are obtained to be included in the uncertainty budget.

**KIBBLE BALANCE FOR GRAM LEVEL MASS MEASUREMENTS**

The redefinition of the kilogram in 2019 in terms of a fixed numerical value of a constant of nature, the Planck constant h, created the opportunity for the realisation of mass at any point on the scale and improvement in the uncertainty at sub gram scales. In this work, part of the route to measurement of mass at small scales at the National Physical Laboratory (NPL) will be described. The aim is to miniaturise a system based on the planned NPL “Next Generation” Kibble balance to a simplified gram level Kibble balance. This is a preparatory step for future work on a micro-electromechanical system (MEMS) scale Kibble balance.

Page 9 of 891 Results 81 - 90 of 8905