DESCRIPTION

This proximity system allows contactless measurement of the relative displacement of moving machine elements. It is particularly suitable for measuring the relative vibration and axial position of rotating machine shafts, such as those found in steam, gas and hydraulic turbines, as well as in alternators, turbo-compressors and pumps. The system is based around a AR401 non-contact transducer and an ARF401 signal conditioner. Together, these form a calibrated proximity system in which each component is interchangeable. The system outputs a voltage or current proportional to the distance between the transducer tip and the target, such as a machine shaft

Working principle

The working principle of the eddy current sensor system is the eddy current effect, which belongs to an inductive measurement principle. The eddy current effect originates from the energy of the oscillation circuit. The eddy current needs to be formed in a conductive material. Introducing an alternating current into the coil inside the sensor probe can form a magnetic field around the probe coil. If a conductor is put into this magnetic field, according to Faraday’s law of electromagnetic induction, eddy currents will be excited inside the conductor. According to Lenz’s law, the direction of the magnetic field of the eddy current is exactly opposite to the magnetic field of the coil, and this will change the impedance value of the coil in the probe. This change in impedance value is directly related to the distance between the coil and the measured object

After the sensor probe is connected to the controller, the controller can obtain the variation of the voltage value from the sensor probe, and based on this, calculate the corresponding distance value. The principle of eddy current measurement can measure all conductive materials