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The temperature influence on magnetic flap level gauges is due to the fact that the transmitter consists of a reed switch strip and a transmitter circuit. In application, the influence of temperature is also divided into two parts. Effect of temperature on reed switch strips: Excessively high temperatures cause changes in resistance impedance. The output will also experience changes. This is because the reed switches inside the reed switch strip are connected by welding. Solder begins to melt at temperatures above 170 degrees. In other words, the temperature inside the reed switch strip must not exceed 170 degrees. Generally, a bundled design is used; the reed switch strips do not come into direct contact with the liquid being measured, but only make partial contact with the wall of the magnetic float level gauge as well as with air. The temperature of these reed switch strips usually drops significantly (for example, in a practical scenario where the ambient temperature is 42 degrees, the temperature of the liquid being measured is 128 degrees, and the temperature of the reed switch strips is 56 degrees). Practical tests show that the local error range is 1–2%, depending on the temperature characteristics of the internal resistance. Impact of the transmitter circuit: Ordinary transmitters lack temperature compensation, and their output also changes as temperature varies. Even if the resistance value of the externally connected reed switch strip does not change at all. Due to the internal self-heating effect of the components, the operation of the transmitter circuit also changes. Through practical testing, the temperature error in this area is approximately 1%. So, how can the temperature effect on magnetic flap level gauge transmitters be eliminated? It is the temperature value measured in practical circuit operations. What we need is a percentage value. Is there a way to measure percentages? Percentages can be measured using the principle of measuring through three lines. It is also less affected by temperature. This principle is similar to that of a potentiometer. The two ends of the potentiometer correspond to 0% and 100% positions, respectively; in the linear region of the potentiometer, the voltage at the middle tap W is directly proportional to the actual percentage. By measuring the voltage at 0% power and at 100% voltage, the entire range can be determined; by measuring the voltage at the intermediate tap and then calculating the ratio, the actual position can be obtained. In such calculations, one assumption is that the resistance is linear. This premise also exists in Figure 1 above. And if the temperature changes, then all these temperatures will change as well; since the temperature characteristics of the resistors remain the same, the influence of temperature can be eliminated when calculating the ratios. Due to the need to use a direct proportion measurement method, it is difficult to implement this with ordinary transmitters; even if it is possible, the circuitry becomes quite complex. Therefore, transmitters equipped with a CPU are used for this purpose. Through the CPU, it is possible to determine the temperature of specific parts of the transmitter circuit, and temperature compensation can be performed based on this temperature. This way, a large part of the temperature influence can be eliminated. At the same time, due to the digital approach, some of the delays present in traditional analog circuits are eliminated, allowing many effects to be removed at one level. The location of the device and the way it is installed also have a certain impact. It is mainly due to the improper placement of the device, which leads to an increase in the impact of temperature. This can be determined based on the actual conditions on site; generally, it is appropriate to operate the circuit of the magnetic flap level gauge at a slightly lower temperature and in a relatively stable location, rather than installing it at the bottom or top merely for the sake of ease of installation. At the same time, for some very special situations, mechanical modifications can be applied to alter the path by which heat is transferred, thereby keeping the transmitter part at a distance from high temperatures. Of course, due to the special conditions in industrial environments where there is a lot of interference, if transmitters equipped with a CPU are used, it is necessary to ensure that the system can function accurately and properly even in the presence of complex interference. For more information, please visit the company’s official website at http://www.yb1518.com/. Please retain this link when reproducing the content!