Ⅰ、Operating principle of integrated eddy sensor:
Eddy current sensor systems work on the eddy current effect, which is an inductive measuring principle. The eddy current effect originates from the energy of an oscillating circuit. Eddy currents can only be formed in conductive materials. By introducing an alternating current into the coil inside the sensor probe, a magnetic field is formed around the probe coil. If a conductor is placed into this magnetic field, eddy currents are excited in the conductor according to Faraday's law of electromagnetic induction. According to Franz's law, the direction of the eddy currents is opposite to the magnetic field of the coil, and this changes the impedance of the coil inside the probe. This change in impedance is directly related to the distance from the coil to the object being measured. Sensor probe connected to the controller, the controller can be obtained from the sensor probe voltage value of the amount of change, and as a basis for the calculation of the corresponding distance value, eddy current measurement principle can measure all conductive materials. Because the eddy current can penetrate the insulator, even if the surface is covered with insulator metal material, can also be used as eddy current sensor of the measured object. The unique coil winding design enables the sensor to be operated in high-temperature measurement environments while achieving a compact profile.
Ⅱ、Application range of integrated eddy sensor:
By measuring the relative position of the metal body to be measured and the probe end, eddy current displacement sensor sensing and processing into the corresponding electrical signal output. The sensor can work reliably for a long time, high sensitivity, strong anti-interference ability, non-contact measurement, fast response speed is not subject to the influence of oil and water and other media, in the large-scale rotating machinery, such as shaft displacement, shaft vibration, shaft speed and other parameters of long-term real-time monitoring is widely used, and has been extended to the satellite launch, material identification, weighing measurement, metal plate thickness measurement, material deformation and other application areas.
Ⅲ、Technical parameters of integrated eddy sensor:
Measuring range | 1mm | 2mm | 4mm | 5mm | 12.5mm | 20mm | 25mm | 50mm |
Probe diameter （standard） | Φ6mm | Φ8mm | Φ11mm | Φ17mm | Φ30mm | Φ40mm | Φ50mm | Φ60mm |
Probe diameter （Countersunk probe） | Φ8mm | Φ8mm | Φ11mm | Φ17mm | / | / | / | / |
Probe diameter （squsre shaped probe） | Φ8mm | Φ8mm | Φ13mm | Φ19mm | / | / | / | / |
probe diameter （circular probe） | / | / | / | / | Φ30mm | Φ40mm | Φ50mm | Φ60mm |
Linearity error (%FS) | ≤±0.25 | ≤±0.25 | ≤±0.5 | ≤±0.5 | ≤±1 | ≤±1 | ≤±1 | ≤±2 |
Repeatability | 0.5um | 0.5um | 1um | 1um | 2um | 2～4um | 2～4um | 2～5um |
Frequency response
| 0～10KHz | 0～8KHz | 0～2KHz | 0～1KHz | ||||
Output signal | 0～5V，0～10V，4～20mA，RS485 | |||||||
Supply voltage | Voltage type+9～36VDC or ±15VDC optional | |||||||
Current type+22～30VDC,RS485 type+12VDC | ||||||||
Working Current | Voltage type＜45mA | |||||||
Current type＜25mA | ||||||||
RS485 type＜40mA | ||||||||
ripple wave | ≤20mV | |||||||
System temperature drift | According to the output signal and the corresponding range and other factors | |||||||
static sensitivity | According to the output signal and the corresponding range and other factors | |||||||
output load | Voltage output：load capacity＜10KΩ | |||||||
Current output：load capacity＜500Ω | ||||||||
Ambient temperature at the time of calibration | （20±5）℃ | |||||||
usage temperature | Probe -30℃～+110℃ | |||||||
Front-end device (integrated box)-30℃～+85℃ | ||||||||
Protection degree | Probe IP67 | |||||||
Front-end device IP65 | ||||||||
Probe cable | standard 2m,can be customized | |||||||
feed cable | standard 2m，can be customized | |||||||
Resolution：
Ⅳ、Definition of integrated eddy sensor wiring:
current type | voltage type | RS485 | |
Brown | power positive +24VDC | power positive +12VDC or +24VDC | power positive +12VDC |
Black | / | power negative 0V | power negative 0V |
Blue | Current OUT | output positive OUT+ | RS485 A+ |
White | / | output negative OUT- | RS485 B- |
Shielding wire | Grounding GND | Grounding GND | Grounding GND |
Ⅴ、Integrated eddy sensor mounting dimensions:
The ML33 sensor system consists of probe, front device (integrated box), cable and accessories.
1、Eddy Current Displacement Sensor Probe
Standard type probe installation size:
Usually the probe is composed of coil, head, shell, high frequency cable and high frequency joint.
In the process of production, the probe head body is generally made of high temperature resistant PPS engineering plastic, and the coil is sealed through the "secondary injection molding" molding. Enable the probe to work reliably in a harsh environment. Since the coil diameter of the head body determines the linear range of the sensor system, we usually use the external diameter of the head body to classify and characterize each type of probe. In general, the linear range of the sensor system is roughly 1 / 2~1 / 4 times of the diameter of the probe head. The ML33 series sensor probes are shown in Fig. (standard type):