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An immersion level gauge operates on the principle that the hydrostatic pressure of the liquid being measured is proportional to its height; it utilizes the piezoresistive effect of diffused silicon or ceramic sensing elements to convert this hydrostatic pressure into an electrical signal. After temperature compensation and linear correction, it is converted into a standard 4-20mA DC current signal for output. The sensor part of the submersible hydrostatic level transmitter can be placed directly into the liquid, while the transmitter part can be fixed using flanges or brackets, making it extremely convenient to install and use. Submersible level gauges are made using advanced isolated diffused silicon sensing elements; by being placed directly into a container or body of water, they can accurately measure the height from the end of the gauge to the water surface, and transmit the level value via a 4–20mA current signal or an RS485 signal. Structure: The two-wire submersible level gauge consists of a special gas guide cable with a built-in capillary tube, a pressure-resistant connector, and a probe. The probe of the level gauge consists of a stainless steel core with a diaphragm at the bottom, covered by a perforated plastic housing. Level measurement essentially involves measuring the difference between the hydrostatic pressure of the liquid on the probe and the actual atmospheric pressure; this pressure difference is then converted into a 4–20mA output signal by a ceramic sensor (attached to a stainless steel diaphragm) and electronic components. Submersible level gauges are widely used in areas such as urban water supply and drainage, sewage treatment, groundwater monitoring, reservoirs, rivers, and the ocean for level measurement. 1. Radio frequency interference mainly includes interference caused by the startup and shutdown of large power equipment, as well as high-order harmonic interference. Such as interference in thyristor rectifier systems, etc. 2. Electrostatic induction: Electrostatic induction occurs due to the presence of parasitic capacitance between two branch circuits or components, which allows charge on one branch to be transferred to the other branch through this parasitic capacitance; hence it is also known as capacitive coupling. 3. Leakage current induction occurs due to poor insulation of components such as mounts, terminals, printed circuit boards, the dielectric material inside capacitors, or their enclosures within electronic circuits. Especially in environments where the humidity is high, the insulation resistance of these insulators decreases, which leads to an increase in leakage current and thus interference. The impact is particularly severe, especially when leakage current flows into the input stage of the measurement circuit. 4. Electromagnetic induction occurs when there is mutual inductance between two circuits; a change in current in one circuit is coupled to the other circuit through a magnetic field, and this phenomenon is known as electromagnetic induction. Such as the leakage magnetic field of transformers and coils, energized parallel wires, etc. 5. Other factors that interfere with the on-site safety production monitoring system: In addition to the disturbances mentioned above, due to the harsh working conditions of submersible level gauge systems, they are also susceptible to mechanical interference, thermal interference, and chemical interference.