For the feedback rod of a locator, is it better to use one based on magnetic induction or one of mechanical type?
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For the feedback rod of valve positioners, some use magnetic induction while others rely on traditional mechanical connections. What do people think is more effective in terms of performance, and what are the advantages and disadvantages of each?
Magnetic induction is superior to mechanical connections: 1. High reliability – there are no connecting parts, which reduces the risk of the feedback rod becoming loose or even falling off due to vibrations at the installation site； 2. High magnetic induction accuracy, large mechanical feedback hysteresis.
The commonly used types for magnetic induction are Fisher and Memosens dual-action ones, as well as those from Metso. The feedback mechanisms of other type of positioners are basically mechanical in nature. As a valve manufacturer, I believe that mechanical transmission is superior to magnetic induction in terms of ease of use, especially when it comes to replacing the positioner. Magnetic induction requires precise installation conditions, such as the vertical alignment of the magnetic strips and the distance between them and the sensing substrate; moreover, installation becomes difficult in tight spaces； However, in terms of reliability, magnetic induction is superior to mechanical transmission, as mechanical transmission is prone to unreliable connections, mainly due to the separation of the feedback rod. When it comes to the overall performance of valves, it is necessary to consider specific brands as a whole.
Neither of the two above is comprehensive. Relatively white.
I’d appreciate some guidance. I merely made distinctions based on everyday use; I’m not really familiar with the specific principles, functions, advantages, and disadvantages. Please clarify so we can learn from each other*