When a magnetostrictive level gauge is installed in an oil tank and inserted to the bottom of the tank (into contact with the tank bottom), it cannot function properly
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At the installation site of the new storage tank, when the telescopic level gauge is installed inside the oil tank, it stops functioning properly (no signal) once the sensor touches the bottom of the tank. This happens with several level gauges; they work normally (with a signal) if the sensor is lifted slightly so that it does not touch the bottom of the tank, or if an insulator is used to separate them from the tank bottom. What is going on? Principle of magnetostriction operation
Magnetostrictive level gauges are usually installed on the side, right? They can also transmit data remotely. Why is it necessary to extend them to the bottom of the tank?
Personally, I think when it’s at the bottom of the tank, there is a force between the float on the level gauge and the metal wall of the tank, which may counteract the torsional stress that should otherwise be generated
Interesting, I don’t quite understand it. Will it be absorbed and no reflection occur?
The two statements mentioned above, namely that “it might offset the torsional stress that should have been generated” and that “it is absorbed and not reflected,” seem to make some sense, but what exactly do they refer to? Could you be more detailed? Thank you!!
Original poster, the principle of a magnetostrictive level gauge is as follows: The core of a magnetostrictive level gauge sensor consists of a measuring element made of ferromagnetic material, usually referred to as a \"waveguide\", along with a movable permanent magnet; the magnet and the waveguide generate a longitudinal magnetic field. Whenever a current pulse (i.e., the “query signal”) is sent out by the sensor’s electronic head and passes through the waveguide, a second magnetic field is generated in the radial direction of the waveguide. At the moment when these two magnetic fields intersect in the waveguide, a \"magnetostrictive\" effect occurs in the waveguide, resulting in the immediate generation of a strain pulse. This pulse, known as a \"return signal,\" travels at ultrasonic speed from the point of generation (i.e., the position measurement point) back to the sensor’s electronic head and is detected by the detector. Accurate measurement of the magnet’s position is determined by a high-speed timer in the sensor circuit, which measures the time interval from the emission of the query signal to the arrival of the response signal; this process is extremely fast and precise. Using the runtime of the computed pulse to measure the position of the permanent magnet provides us with an absolute position reading, and there is no need for regular recalibration or concern about the value returning to zero in the event of a power outage. Contactless measurement eliminates the problem of mechanical wear, ensuring optimal repeatability and durability. If the bottom of the magnetostrictive level gauge rod (waveguide) is in close contact with the bottom of the tank, it will cause the rod (waveguide rod) to deform, and the waveguide wire inside it will also deform, resulting in a distorted magnetic field and the loss of the level signal. The two measuring rods make contact with the bottom of the tank; if the sensor is not properly designed, has poor interference resistance and inadequate insulation, it can cause changes in the magnetizing pulses, resulting in signal loss. I suggest using the American KETK products, which would be better.
Take a look at how instruments of this type work, and you’ll probably understand the reason. Hehe