Yokogawa two-wire magnetic flowmeter uses dual-frequency excitation

The new Yokogawa ADMAG AXR is a two-wire magnetic flowmeter that achieves high performance by using dual-frequency excitation technology.

To date, most magnetic flowmeters have been of the four-wire type, where high accuracy and performance are achieved by using a dedicated power-supply cable that is separate from the signal cable used for the measurement current output. The two-wire type, on the other hand, uses just one pair of wires for current output and power supply, offering significantly lower installation costs by requiring neither a dedicated power supply cable nor a power-supply unit.

Despite these benefits, conventional two-wire magnetic flowmeters do have limitations in terms of measurement accuracy and stability, and as a result have not been well accepted in the process automation sector. Now, however, Yokogawa has developed the dual-frequency excitation technique for minimising electric noise in two-wire models to a level comparable to that of four-wire magnetic flowmeters, thereby achieving the high measurement accuracy and stability needed for use in control loops.

The Yokogawa dual-frequency excitation method uses high-speed digital processing to execute the complex algorithms required to enhance stability and performance while at the same time minimising power consumption.

A further performance enhancement is provided by a new coil configuration. Because a two-wire magnetic flowmeter has a limited power-supply capability, the current supplied to the excitation coil is normally too weak for signals to be differentiated from electrical noise. To resolve this problem, Yokogawa has adopted a new high-density coil construction method that enables a stronger magnetic field to be generated with a low current.

Yokogawa has also found ways to minimise the noise level by smoothing the inner surface of the measuring tube and developing an electrode that generates very little noise. As a result, the Admag AXR makes it easy to differentiate signals from electrical noise, thereby achieving a measurement accuracy comparable to that of a four-wire magnetic flowmeter.

User friendliness in the new Admag AXR has been enhanced through the addition of a full dot-matrix LCD display capable of displaying messages in six different languages, enabling magnet switches to be operated without opening the cover, the addition of an electrode adhesion diagnosis function, and a design change that allows the orientation of the converter to be changed on site.

The elimination of the need for a dedicated power-supply unit and power-supply cable has allowed a sharp reduction in instrumentation cost. The lower power consumption of the two-wire instrument also reduces running costs. The Admag AXR is ideally suited to fluid flow measurement in a variety of industries including chemicals, iron & steel, and food & beverages.

Endress+Hauser weathering the crisis

The effects of last year’s economic crisis have been felt at Endress+Hauser, with sales dropping for the first time in the company’s history. But the international Swiss-based Group remained profitable during the past year and the financial power of the family-owned business even increased. After a good start in 2010, Endress+Hauser expects sustained recovery and considerable growth.

Speaking at the Annual Media Conference of Endress+Hauser AG in Basel, Chief Executive Officer Klaus Endress said the company had “experienced one of the most difficult years in its history.” Net sales of the Group fell to €1.096 billion in 2009 (–9.5%). The number of employees, however, remained virtually unchanged, with a staff of 8,419 worldwide at the end of 2009 – only 15 fewer than the year before (–0.2%). “We wanted to avoid job losses,” said Klaus Endress. “We wanted everybody to be on board when business started to gain momentum again.” Endress+Hauser created 2,125 jobs over the past five years, 1,418 of which in Europe. In the region around Basel between Switzerland, France and Germany alone, 775 new jobs were created during that period.

The setback was particularly painful in the chemical industry, one of the company’s mainstays. The slump in sales was heftiest in the established industrialised countries such as the United States, Germany and Japan, said Chief Operating Officer Michael Ziesemer, the CEO’s deputy. Business declined sharply in Russia, but recovered early in China, where sales reached the same level as 2008. India, Korea, the Middle East and Latin America showed positive developments. All in all, Endress+Hauser fared better than the process automation industry as a whole which shrank by 16%.

Worldwide sales and production network strengthened

Despite the crisis, Endress+Hauser continued to strengthen its global sales and production network, setting up its own branch office in Qatar to intensify business in the Middle East and opening a sales centre in Lithuania to improve customer support in the Baltic countries. With €67.2 million (–37.1%) investments were well below the 2008 reference, but no important projects were stopped or postponed. “We have invested over €400 million in the course of the past five years,” stressed Fernando Fuenzalida.

Additionally, Endress+Hauser increased its R & D expenses to €94.1 million (+6%), accounting for 9.6% of net sales. 200 patent applications – as many as in 2008 – demonstrate the company’s unbroken powers of innovation. By acquiring a majority in the English company MHT Technology Ltd, Endress+Hauser strengthened its competence in tank gauging and in tank farm automation.

A good start to the new year

Endress+Hauser has had a good start to the new year. After just four months, incoming orders increased by double-digit figures against the previous year. The growth in sales is well above the cautious target of 5-6%. Business in the US and Germany has picked up, Russia is catching up fast and China shows dynamic growth again. Only the Scandinavian countries are still deep in the recession. If this development continues, the Group anticipates that as much as 10% growth is well within reach.

Klaus Endress calls for caution: “Basically, the causes of the economic crisis are still with us.” Future developments are characterised by many uncertainties. “2009 was a difficult year and 2010 won’t be much easier,” the CEO believes. “We are pretty certain that the crisis will be with us for some time to come.”