As the core equipment of power production, the safe and stable operation of steam turbine is of vital importance. Shaft vibration is one of the key parameters for measuring the operating status of steam turbine. PR6423/000-111 eddy current sensor is widely used in the measurement of turbine shaft vibration. It is based on the principle of eddy current effect. It generates high-frequency magnetic field through the preamplifier to sense the eddy current changes on the surface of metal conductor (shaft), thereby measuring the vibration and displacement of the shaft. This series of sensors has the advantages of wide operating temperature range and high protection level. However, in practical applications, the output signal of PR6423/000-111 sensor may be subject to various electromagnetic interferences, generate high-frequency noise, and affect the measurement accuracy and equipment safety. This article will analyze the possible sources of electromagnetic interference for the high-frequency noise problem that may occur in PR6423/000-111 sensor, and propose corresponding treatment methods.

1. Working principle and characteristics of PR6423/000-111 sensor

PR6423/000-111 eddy current sensor usually consists of sensor probe, preamplifier and cable. The preamplifier generates a high-frequency magnetic field, and the probe senses the eddy current changes on the shaft surface and converts these changes into electrical signal output. The output signal is usually a 4-20mA current signal or a ±5V voltage signal. This analog signal is susceptible to electromagnetic interference.

2. Analysis of possible electromagnetic interference sources

Based on the general knowledge of electromagnetic interference and combined with the application characteristics of the PR6423 shaft vibration probe, the possible interference sources mainly include the following aspects:

• Power supply interference: The power supply system at the turbine site may have fluctuations, harmonics and other interferences, which will be introduced through the sensor power supply circuit and affect the stability of the output signal.
• Electromagnetic radiation of the equipment itself: Inverters, high-power motors, radio frequency equipment, etc. may generate strong electromagnetic radiation, which will interfere with the sensor signal through spatial coupling.
• Cable and grounding problems: The sensor cable is not shielded, or the shielding layer is poorly grounded, which will cause electromagnetic interference to enter through cable coupling. In addition, unreasonable grounding system design and problems such as grounding loops will also introduce interference.
• Environmental factors: The sensor installation location is close to strong electromagnetic field sources, such as high-voltage transmission lines, radar transmitters, etc., which will also be interfered.

3. Corresponding treatment methods

For the above possible interference sources, the following corresponding treatment methods can be adopted:

• Optimize the power supply system: use a stabilized power supply, install a filter, suppress power supply fluctuations and high-frequency harmonics.
• Shield electromagnetic radiation: shield the interference source, such as installing a metal shielding cover, or adjust the sensor installation position to stay away from strong electromagnetic field sources.
• Improve cables and grounding: always use shielded cables and ensure that the cable shielding layer is reliably grounded. Avoid parallel wiring of cables with other strong cables. Optimize the grounding system design to avoid grounding loops.
• Environmental adaptability: choose a suitable sensor installation location away from strong electromagnetic field sources. If necessary, perform additional shielding on the sensor.
• Check the connector: regularly check whether the sensor connector is loose or corroded to ensure reliable connection.
• Signal processing: consider using a preamplifier with good anti-interference performance, and filter the sensor output signal to filter out high-frequency noise.

PR6423/000-111 eddy current sensor plays an important role in turbine shaft vibration measurement. In order to ensure measurement accuracy and equipment safety, high-frequency noise must be taken seriously. By analyzing possible sources of electromagnetic interference and taking appropriate treatment methods, noise interference can be effectively reduced and the quality of sensor signals can be improved. In practical applications, various factors should be considered comprehensively based on the specific conditions of the site to select an appropriate treatment solution.

When looking for high-quality, reliable eddy current sensors, YOYIK is undoubtedly a choice worth considering. The company specializes in providing a variety of power equipment including steam turbine accessories, and has won wide acclaim for its high-quality products and services. For more information or inquiries, please contact the customer service below:
E-mail: sales@yoyik.com
Tel: +86-838-2226655
Whatsapp: +86-13618105229
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