Magnetostrictive level gauge and float level gauge
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Hello, dear sea friends! Is a “magnetostrictive level gauge” the same as a “float level gauge”? If not, what is the fundamental difference between them? What are the differences in the situations where they are used? Thank you!
It’s definitely different; you can just look it up online. In magnetostrictive effect, there is a metal rod, with a floating ball that slides on the outside – the floating ball doesn’t have a rod
He was referring to that type of float level gauge with a rod
Magnetostriction is a change in magnetic field, while the float level gauge operates through mechanical action. The appearance is basically the same
I am very grateful for the advice from the user on the 4th floor. You just mentioned that the magnetostrictive level gauge is currently the most accurate type of level gauge available
A magnetostrictive level gauge consists of a measuring rod (with a magnetostrictive wire inside), a float (with a permanent magnet inside), and a transmitter, as shown in the figure. The current pulse generated by the transmitter circuit unit is transmitted downward along the magnetostrictive wire, generating an annular magnetic field. A float is attached to the measuring rod, and this float moves up and down along the rod as the liquid level changes. A magnet is installed inside the float, which generates a magnetic field as well. When the current magnetic field meets the float’s magnetic field, their magnetic fields interact to generate an instantaneous torque, which creates a mechanical torsional wave pulse on the magnetostrictive wire. This mechanical torsional wave is transmitted back at a certain speed to the electronic components, which detect the pulse. By measuring the time difference between the emitted electrical pulse and the returning torsional wave pulse, the measured liquid level height can be calculated. http://yunrun.com.cn/upload/201807/26/201807260025196853.png Float level gauges also operate on the principle of buoyancy and magnetic coupling. There are three types of such gauges: those with magnetic floats installed on the side, those with them installed at the top, and those with them installed at the bottom. They can be used to measure both liquid levels and interface positions. As the liquid level in the container under test rises or falls, the magnetic float moves up and down as well. The magnetic field lines from the magnet inside the float pass through the measurement conduit, and through magnetic coupling, the on/off state of the reed switch is controlled, thereby changing the resistance value of the resistance component connected to the reed switch. The sensing and transmission principle is as shown in the figure: a voltage division circuit is used to measure the liquid level, with the generated voltage being proportional to the liquid level. The transmitter performs V/I conversion, and ultimately the float level gauge outputs the liquid level measurement signal in a 4-20mA format, either in two-wire or three-wire configuration. Changhui Instruments yunrun.com.cn/ http://yunrun.com.cn/upload/201807/25/201807251512200103.png
In a magnetostrictive level gauge, the function of the magnetic floating ball is to cause the pulses in the guided wave wire to reflect back; the circuit measures the time difference between these pulses, and the liquid level value is determined based on this time difference. In a magnetic float level gauge, the function of the magnetic float is to close the reed switch and affect the resistance of the bridge arms; the direct measurement in the circuit is the differential voltage of the bridge, and the liquid level value is determined by converting this differential voltage. The measurement resolution of a magnetostrictive level gauge is high, around 1 mm. The resolution of a magnetic float level gauge is lower, around 2 cm. The accuracy of both types is essentially the same – it is determined by the amount of movement of the floating ball. Indeed, there is a difference in precision between the two; no matter how large that difference is, it will not exceed 2 cm. Magnetostrictive level gauges have measurement blind zones at both ends; magnetic float level gauges also have such blind zones, preventing measurement of the very bottom level. Magnetostrictive level gauges can operate continuously without failure for long periods of time. Maglev level gauge has a short continuous fault-free operation time. This is due to the reed in the dry contact switch – it fails to engage properly or to disengage properly, resulting in a relatively high frequency of intermittent failures. The length of those two is based on the premise that the magnetic floating ball does not get stuck. If the float ball gets stuck frequently, then they are basically the same as a single ball. Magnetostrictive level gauges are expensive; magnetic float level gauges are cheap, designed for those on a tight budget or who are idle.
Magnetostrictive level gauges have the highest accuracy – wrong! This is something that some people say on purpose to mislead others, spreading nonsense. The best! Stop talking nonsense, who’s talking nonsense? Brother, I’ve got big claws like pig’s hooves – I’ll slap that guy’s mouth.
I am extremely grateful to all the fellow sailors for their advice; I have learned a great deal from it!
The working principle of a magnetic flap level gauge should be the same as that of a float level gauge, right? Are the red and white magnetic beads inside the magnetic flap float balls?