Axial displacement eddy current probe

Anhui WanlongProbe Sensor, Transmitter, Protector, Monitoring Instrument

Wanlong Electric Axial DisplacementSensor eddy current probeQBT-3800XL-A02-X05-L65Brand: Anhui Wanlong Electric

Wanlong ElectricAxial displacement eddy current sensor3800XL-A02-X50A-L70-M01-K002Brand: Anhui Wanlong Electric

The typical application of sensors is eddy current sensor systems, which are widely used in industries such as power, petroleum, chemical, metallurgy, and some scientific research institutions. Online measurement and protection of radial vibration, axial displacement, key phase shifter, shaft speed, differential expansion, eccentricity, rotor dynamics research, and part size inspection of large rotating machinery shafts such as steam turbines, water turbines, blowers, compressors, air compressors, gearboxes, and large cooling pumps.

Application areas:
The online monitoring and fault diagnosis of displacement, vibration, speed, oil film thickness and other parameters of equipment such as steam turbines, water turbines, generators, blowers, compressors, gearboxes, etc. widely used in industries such as power, petrochemicals, metallurgy, etc.
Technical specifications probe: working temperature -50~+175 ° C, temperature drift ≤ 0.05%/° C preamplifier: working temperature -50~+120 ° C, temperature drift ≤ 0.05%/° C
Frequency response: 0-10kHz; The amplitude frequency characteristics are -1% at 1kHz and -5% at 10kHz; Phase frequency characteristics -1 ° at 1kHz and -100 ° at 10kHz
Output characteristics:
1. Negative voltage output power supply: -18Vdc to -24Vdc, power consumption ≤ 12mA (excluding output current)
2. 4-20mA current output power supply:+18Vdc~+30VDC power consumption ≤ 12mA (excluding output current)

Application of Anhui Wanlong Electric Series Eddy Current Sensors:
Axial position measurement: It can indicate the wear of thrust bearings or the potential for bearing failure.
Radial vibration measurement: It can indicate the working condition of bearings and measure mechanical faults such as rotor imbalance, misalignment, and shaft cracks.
The average radial position of the shaft inside the bearing: it can be used to determine the azimuth angle, and it is also an indicator of whether the speed is stable and whether the shaft is aligned.
Keyphasor signal: It is used to measure the rotational speed and phase angle of the shaft.
Eccentricity: For large and small turbine machinery, the bending of the shaft, i.e. eccentricity, needs to be measured during startup.

It is a non-contact linearized sensing system composed of a preamplifier and an eddy current probe. Eddy current sensors are mainly used to measure the static and dynamic distance between the probe and the object being measured. The object being measured is generally ferrite, and the alternating electromagnetic field of the probe is absorbed by the ferrite. The electronic circuit of the sensor senses and processes this change, thereby obtaining the displacement of the object being measured. It has the advantages of good long-term work reliability, wide measurement range, high sensitivity, high resolution, fast response speed, strong anti-interference, and is not affected by oil and other media. Therefore, it has been widely used in online status monitoring and fault diagnosis of large rotating machinery.

Mainly used in industries such as power, petroleum, chemical, metallurgical, scientific research, etc., it can measure the radial vibration, axial displacement, key phase device, shaft speed, expansion difference, eccentricity, as well as rotor power research and part size inspection of large rotating machinery shafts such as steam turbines, water turbines, blowers, compressors, gearboxes, cooling pumps, etc. online.

The probe consists of an inductor, a protective cover, a stainless steel housing, a high-frequency cable, a high-frequency connector, etc. It can measure the gap variation between the surface of the measured object and the probe end face, and is an essential component of the sensor. To avoid twisting the cable due to rotating the probe housing during installation, the cable length of all probe parts is only 1 meter ± 5%, and the remaining cable length is supplemented by extension cables. The preamplifier is a part of the system, which includes the oscillation generation, linear detection, filtering, linear compensation, amplification and other circuits of the entire sensor system. It converts the distance changes between the probe and the measured metal into corresponding voltage signal changes through extension cables. Probe specifications and linear range:
Φ3(0.5～０.８mm)、Φ4(1mm)
5 (2mm), 8 (2mm), 10 (3mm), 11 (4mm), 14 (4 or 5mm), 16 (6 or 7mm), 18 (8mm), 22 (10mm)
Φ 25 (12.7mm), Φ 32 (12 or 14 or 16mm), Φ 36 (18 or 20mm)
Φ50(25mm)。 -24V power supply: -4~20V, -2~-18V output ± 12~15V power supply: 0-5V, 0~10V, -5~5V -10~+10V output. +24V power supply: 4-20mA, 1-5V output. The system is widely used in industries such as power, petroleum, chemical, metallurgy, and some scientific research institutions. Online measurement and protection of radial vibration, axial displacement, key phase shifter, shaft speed, differential expansion, eccentricity, rotor dynamics research, and part size inspection of large rotating machinery shafts such as steam turbines, water turbines, blowers, compressors, air compressors, gearboxes, and large cooling pumps.

Axial displacement measurement
For many rotating machinery, including steam turbines, gas turbines, water turbines, centrifugal and axial compressors, centrifugal pumps, etc., axial displacement is a very important signal, and excessive axial displacement will cause significant damage to the mechanism. The measurement of axial displacement can indicate the axial clearance or relative instantaneous displacement changes between rotating and fixed components to prevent machine damage. Axial displacement refers to the gap between the internal rotor of a machine and the thrust bearing along the axis direction. Some mechanical faults can also be identified through the detection of axial displacement:
● Wear and failure of thrust bearings ● Wear and failure of balance pistons
● Loosening of thrust flange ● Locking of coupling, etc.
The measurement of axial displacement (axial clearance) is often confused with axial vibration. Axial vibration refers to the rapid change in distance between the surface of the sensor probe and the measured object along the axial direction. This is a type of axial vibration, represented by peak to peak values. It is unrelated to the average gap. Some faults can cause axial vibration. For example, the vibration and misalignment of the compressor.
Vibration measurement
By measuring radial vibration, one can observe the working condition of the bearing and also the imbalance of the rotor, which may indicate moderate mechanical faults. Can provide the information required for mechanical condition monitoring of the following key or basic machinery:
·Industrial turbines, steam/gas compressors, air/special purpose gases, radial/axial
·Expansion machine, power generation turbine, steam/combustion/water conservancy
·Electric motor and generator
·Exciter and gearbox
·Pump and Fan
·Blower · Reciprocating Machinery
Vibration measurement can also be used for continuous monitoring of general small machinery. This provides important information for early identification of various mechanical faults.
·Synchronous vibration of the shaft and oil film instability
·Rotor friction and loose components
·Loose bearing sleeve and compressor kick vibration
·Rolling component bearing failure · Radial preload, internal/external including misalignment
·Bearing Babbitt alloy wear, excessive bearing clearance, radial/axial
·Balance (blocking) piston wear/failure · Coupling "locked"
·Axis bending and cracking
·Uneven air gap and gear meshing problem in electric motors
·Turbine blade channel resonance and impeller passage phenomenon
Eccentricity measurement is the measurement of the degree of shaft bending at low speeds, which can be caused by the following conditions:
·The original mechanical bending caused by temporary temperature rise inevitably results in some downward bending in a stationary state, sometimes also known as gravity bending.
The measurement of eccentricity is crucial for evaluating the overall mechanical condition of rotating machinery. Especially for steam turbines equipped with turbine monitoring instrument systems (TSI), eccentricity measurement has become an essential measurement item during start-up or shutdown. It allows you to see the magnitude of axis bending caused by heat or gravity. The eccentric position of the rotor, also known as the radial position of the shaft, is often used to indicate bearing wear and the magnitude of the load. If the situation is caused by misalignment, it is also used to determine the azimuth angle of the shaft, which can indicate whether the rotor is stable.
Differential expansion measurement is crucial for steam turbine generator units. Due to differences in metal materials, thermal expansion coefficients, and heat dissipation during start-up and shutdown, the thermal expansion of the shaft may exceed that of the shell; Possible contact between rotating and stationary components of the turbine, such as the casing, nozzle, pedestal, etc., may result in damage to the machine. Therefore, the measurement of differential expansion is very important.
For all rotating machinery, speed measurement requires monitoring the speed of the rotating machinery shaft, which is an important indicator for measuring the normal operation of the machine. The performance of eddy current sensors in measuring rotational speed is unparalleled by any other sensor. It can respond to both zero and high rotational speeds, and has strong anti-interference performance.