First, the status quo of technological development
Today, with the rapid development of science and technology, flow meter manufacturers around the world are striving to apply the latest technology to the design of products to improve product performance and expand the use of products. Specific performance in the following areas:
1. In terms of instrument intelligence. The intelligence of the instrument mainly refers to the functional intelligence. In recent years, various flowmeter manufacturers have continuously applied new microprocessors to their products, enabling them to have the ability to control the entire working process through software. Therefore, new features such as ATC detection, forward/reverse flow measurement, nonlinear compensation, digital filtering, and zero-point calibration have appeared in the products of various electromagnetic flowmeter manufacturers one by one. In addition, the electromagnetic flowmeter manufacturers are constantly improving the design of electromagnetic flow sensors to achieve the purpose of improving the electromagnetic flowmeter's intelligence level. At present, companies such as Fischer & Porter, Aichi Shiji Electric, Toshiba, and IllIle have successively demonstrated or introduced non-full-tube electromagnetic flowmeters. The electromagnetic flowmeter breaks through the limitation that the traditional electromagnetic flowmeter can only accurately measure the full-pipe flow, and realizes a significant leap in electromagnetic flow detection technology. In non-full-pipe electromagnetic flowmeters that have been introduced to the market, Noe's products have a measurement error of <-1% FS and have become leaders in this category.
2. In the field of excitation technology and measurement performance improvements. Measurement accuracy and zero-point stability are critical for electromagnetic flowmeters, and these specifications are closely related to the excitation technology used by the flowmeter. In order to improve the measurement performance of electromagnetic flowmeters, flowmeter manufacturers around the world are constantly conducting research on excitation technology. With the development of electronic technology, the excitation technology has evolved from DC excitation and AC excitation to low frequency rectangular wave excitation and three-value low-frequency rectangular wave excitation and other technical stages. At present, low frequency rectangular wave excitation has become the mainstream of electromagnetic flowmeter excitation methods at home and abroad. However, the application practice found that low-frequency rectangular wave excitation immunity against flow noise and resistance to slurry noise is not ideal. In response to this shortcoming, some foreign electromagnetic flowmeter research institutions have already adopted several improved excitation methods such as: dual frequency excitation technology, adjustable frequency square wave excitation technology, pulsed AC excitation technology. Among them, the pulsed AC excitation technology introduced by Turbo Messtechnik of Germany is the most prominent. The electromagnetic flowmeter produced by this technology has a flow signal amplitude that is 10 times that of a normal rectangular wave excitation instrument and has a high signal-to-noise ratio.