Flow transmitter

Sensor classification
1, water flow transmitter
The water flow sensor is mainly composed of copper valve body, flow rotor assembly, steady flow assembly and Hall element. It is fitted to the inlet end of the water heater to measure the inflow rate. As water flows through the rotor assembly, the magnetic rotor rotates and the speed varies linearly with the flow rate. Hall element output corresponding pulse signal feedback to the controller, by the controller to judge the size of water flow, adjust the current control proportional valve, so as to control the gas volume through the proportional valve, avoid the phenomenon of warm summer and cool winter gas water heater in the process of use. The water flow sensor fundamentally solves the disadvantages of high starting water pressure of differential pressure water-gas linkage valve and dry burning of flap type water valve. It has the advantages of sensitive response, long life, quick action, safe and reliable, easy connection and low flow (1.5L/min), and is loved by the majority of users.
2, plug-in flow transmitter
The working principle of the plug - in flow sensor is based on Faraday's law of electromagnetic induction. In the electromagnetic flow sensor, the conductive medium in the measuring tube is equivalent to the conductive metal rod in the Faraday test, and two electromagnetic coils at the upper and lower ends generate a constant magnetic field. When a conductive medium flows through, an induced voltage is generated. Two electrodes inside the tube measure the induced voltage generated. The measuring tube is electromagnetic isolated from the fluid and the measuring electrode by a non-conductive lining (rubber, teflon, etc.).

Technological innovation,
The global sensor market is growing rapidly in the midst of ever-changing innovation. Experts point out that the main technology in the field of sensors will be extended and improved on the existing basis, countries will compete to accelerate the development and industrialization of a new generation of sensors, the competition will be increasingly fierce. The development of new technologies will redefine the sensor market in the future, such as wireless sensors, fiber sensors, smart sensors and metal oxidation sensors and the emergence of new sensors and market share expansion.
Prospects for development
According to the sensor Market report, the global sensor market capacity in 2008 was $50.6 billion, and the global sensor market is expected to reach over $60 billion in 2010. According to the survey, Eastern Europe, Asia Pacific and Canada are the fastest growing regions in the sensor market, while the United States, Germany and Japan remain the largest regions in sensor market distribution. Worldwide, the fastest growing sensor market is still the automotive market, the second is the process control market, good communication market prospects. Some sensor markets such as pressure sensors, temperature sensors, flow sensors, level sensors have shown the characteristics of mature markets. The market size of flow sensor, pressure sensor and temperature sensor is the largest, accounting for 21%, 19% and 14% of the whole sensor market respectively. The main growth in the sensor market comes from emerging sensors such as wireless sensors, MEMS(micro-electro-mechanical Systems) sensors, and biosensors. Wireless sensors are expected to grow at a cagR of more than 25% from 2007 to 2010.
Selection method
Therefore, users should choose the right sensor according to their own needs when selecting the flow sensor. Many users do not have the same level of requirements for the use of sensors, so the selection of standards are not the same. If professional data and results are needed, national standards should be selected. However, if the analysis is done as a simple instrument in the enterprise, the enterprise standard can be selected. If you want to buy flow sensor, we must carefully consider, and choose some quality assurance, better use of the sensor. Because a lot of people think that the new sensors, the more sophisticated they are, that's a very one-sided idea. A new product with mature technology is a good product.
Accurate measurement of flow has become very important in many economic fields. Sensors are now used for almost everything that measures flow. The sensor senses the flow of fluid and converts it into a usable output signal, making the operation easier and more convenient. The amount of flowing objects passing through per unit time is called flow, and there are different flow sensors for different objects. Flow sensor types are often distinguished by measuring media and measuring methods.
Flow sensors are generally used for the flow of medium fluid in industrial pipelines. In general, there are a variety of media such as gas, liquid and steam, and several flow sensors can be used for these types of media. The first is vortex street flow sensor.
There is also an ultrasonic flow sensor, with the development of ultrasonic technology, in general, the use of ultrasonic flow sensor can measure the flow of most flowing objects. Ultrasonic flow sensor has a variety of measurement methods, each method has its own characteristics, we should be based on the nature of the flow measured. Velocity distribution, location of pipeline installation and requirements for measurement accuracy are selected. Due to the widespread problem of large pipe diameter and large flow measurement in industrial flow measurement, this is because the general flow sensor with the increase of measuring pipe diameter will bring difficulties in manufacturing and transportation, cost increase, increase in energy loss, installation of not only these shortcomings, ultrasonic flowmeter can be avoided. Ultrasonic flow measurement accuracy of the flow sensor is almost not affected by measurement of body temperature, the effects of parameters such as pressure, viscosity, density, and can be made into non-contact and portable measuring instrument, and can solve the other type is difficult to measure by instrument of strong corrosion resistance, electrical conductivity, radioactive and flammable and explosive medium flow measurement problem.
There are more factors affecting the flow sensor, more than ten kinds of principle, not less than 200 kinds of types, some people on the field of more than a thousand flow sensors in the United States, found that 60% of the method is not suitable, and even if the method is suitable, and about half of the installation and layout of the problem. Making the right choice is not easy. To sum up, the correct choice of flow sensor depends on six factors: sensor technical parameters, fluid characteristics, flow state, installation, environment, and economy.

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