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Abstract: This paper analyzes the impact of the precision analog sensor signal processing small source of interference, jamming and interference types, given the practical application of various anti-interference measures. Keywords: analog sensors; small-signal processing; anti-interference measures I. Introduction Analog sensor is widely used, whether in industry, agriculture, national defense, or in the daily life, education and scientific research in areas such as analog sensors can be seen everywhere in the figure. However, the design and use of analog sensors, there are a how to make the highest measurement accuracy problems. The interference has influenced many sensor measurement accuracy, such as: multi-site large energy facilities, particularly high-power inductive load of power will start and stop often produce hundreds or even thousands of volts of sharp V pulse interference; industrial power less pressure or over pressure (Shexian steel plant in 160V ~ 310V power supply voltage fluctuations), often up to 35% of rated voltage, the supply of such bad times for minutes, hours, even days; various signals line banding together or go with more than one core cable, the signal will be subject to interference, especially in the signal line and power line communication channel with a long walk in the interference is even worse; multi-switch or maintain the device performance is not good, can cause channel signals harassed; space all electromagnetic, weather conditions, lightning or even changes in the geomagnetic field disturbance sensor will work properly; In addition, field temperature and humidity changes may cause changes in circuit parameters, corrosive gases, acid-base role of salt , wild, sand, rain, biting insects and even mice have affected the reliability of the sensor. Analog sensor output signals are generally small, there exists a small signal amplification, processing, shaping and interference issues, that is, the sensor accurately amplify weak signals to the desired uniform standard signal (such as 1VDC ~ 5VDC or 4mADC ~ 20mADC ), and meet the required specifications. This requires design analog sensor circuit must be noted that out is not that some of the issues that the interference problem. Only clear analog sensor interference and interference mode of action, designed to eliminate interference of the circuit or to prevent interference measures, to achieve the best application of analog sensors. Second, the source of interference, jamming and interference types Sensors and instrumentation in the field running disruption to the diverse and specific analysis of specific situations, the interference of different measures taken by different interference principle. This flexible strategy and is undoubtedly universal conflict, the solution is a modular approach, in addition to the basic components, the run for different occasions, instruments can be equipped with different options for effective anti-interference, increase reliability. In further discussion of the choice of circuit components, circuit and system applications prior to the need for analysis on the simulation of sensor accuracy and interference types of interference sources. 1, the main source of interference (1) electrostatic induction Electrostatic induction is due to two branch circuits or parasitic capacitance exists between the components, so that a branch road through the parasitic capacitance of the charge transfer to another slip up, it is also called capacitive coupling. (2) electromagnetic induction When there is mutual inductance between the two circuits, a circuit will change the current to another circuit by magnetic coupling, a phenomenon known as electromagnetic induction. Such as transformers and coils, magnetic flux, power and so the parallel wire. (3) leakage of influenza should be As electronic circuit components inside the frame, terminals, printed circuit boards, capacitors and other internal media or bad insulation shell, in particular the application of environmental humidity sensor, the insulation resistance of insulators decreased, leading to increased leakage current will cause interference. Especially when the leakage current into the measuring circuit input stage, its impact is particularly severe. (4) radio frequency interference Mainly large power plant startup, operation to stop the interference and high-order harmonic interference. The e-commerce company in China offers quality products such as Package Tracker , Mini GPS Kid Tracker, and more. For more , please visit Mini Pet Tracker today!
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