In the recent years, the theory of electromagnetic flow meters is being developed to describe more complicated problems in the measurement such as multiphase flow and flow reconstruction. This paper focuses on a method for the reconstruction of flow patterns in two-dimension domain by electromagnetic flow induction.
Theoretical analysis and numerical simulation are completed based on the idea of flow pattern reconstruction by means of electromagnetic flow induction. Main concepts of the theory and reconstruction methods are summarized. A spectrum expanding method is used for flow pattern reconstruction in two-dimensional domain. General expressions for the weight function W and flow velocity distribution V are obtained by series expansion. Examples of the weight function in the case of 4 pairs of electrodes and 2 pairs of magnetic coils, and some flow velocity distributions are studied. Matrix A and signal vector S are worked out. Some cases of symmetrical and asymmetrical flows are reconstructed using the software of MATLAB. The results are showed and discussed.

The aim of this paper is to review both the performance and the advances made over the last four years in the operation of buried battery electromagnetic water flowmeters installed within a distribution network.
The authors will review the original design criteria and installation decisions in the light of subsequent experience, highlighting the obvious and not so obvious lessons learned.
They will, then, outline some of the methods used to assess the condition of the buried meters in-situ and illustrate the very real changes in performance which have been achieved through optimisation of meter software parameters.
Further to this optimisation, the developing role of GSM equipped meters is illustrated and the case made for the economic pursuit of wholelife costing through interactive monitoring of performance.
The increasing demands for Traceability and Data Quality, driven by Water Industry Regulators, are discussed and the role of meter verification, including static electronic methods such as the ABB CalMaster, is assessed.
Finally, the need for Users to clearly define their Application Needs and to be able to both Specify and understand the range of performance being offered by Manufacturers is discussed with illustrations linked to the new International CEN, ISO and OIML water meter Standards.

The aim of this paper is to present recent advances which have been made in applying electromagnetic insertion probes to the verification of bulk supply water flowmeters.
Building on laboratory work undertaken to define the baseline calibration of this type of insertion probe the authors illustrate how Traceability. Performance and Productivity have been dramatically improved through the use of intelligent software. Key elements that are discussed relate to the increasing demands of Water Industry Regulators for the introduction of Quality Management principles at the Site and Data level and how this has crucially influenced development of the applied technology. The on-site verification of bulk supply meters in the range 150mm and above is illustrated in detail and the current technique is contrasted with existing methods to show how major improvements have been achieved; delivering improved Traceability, uncertainty, performance and productivity. The authors will conclude by suggesting that through the use of the improved methods described the case for wider use of the electromagnetic insertion flowmeter, not only as the primary tool for verifying bulk water supply meters but also as a valid technique which can be applied in situations with poor hydraulics, can be made.

Vortex flowmeter based on pieazoelectric transducer is subjected to noise disturbances caused by pipe vibrations and fluid turbulence during measurement. According to the characteristics of the fluid field near the bluff body, the method using differential pressure between two sides of the bluff body to measure vortex frequency is presented in the paper. Numerical simulations have been carried out to help the optimally sensor structure design. The experimental results show that this method is effective to measure vortex frequency and has robustness to disturbances.