Displacement Sensor

Resistive Transducer
A resistive transducer is also called a variable resistance transducer because it works on the principle of variable resistance transduction. This transducer is one of the most frequently used displacement transducer, used to measure different physical quantities like pressure, displacement, force, temperature, and vibrations and converts them into an electrical signal.

Capacitive Transducer
A capacitive transducer is a passive transducer that works by using external power. This transducer is mainly used to measure pressure, displacement, movement, force, velocity & other parameters. This transducer works on the variable capacitance principle, so the capacitance of this transducer changes due to many reasons like dielectric constant, overlapping of plates, and change within distance in between the plates. This is a passive type where equal & opposite charges are generated on the plates because of the applied voltage across the capacitor plate which is separated through the dielectric material.

Linear Variable Differential Transformer
The LVDT or linear variable differential transformer is one kind of displacement transducer. This transducer includes three symmetrically spaced coils where the primary coil is the center coil & remaining two coils are secondary coils. These are mainly connected in series & positioned equally with respect to the main coil.

Inductive Transducer
An inductive transducer is one kind of displacement transducer that works on the transduction or electromagnetic induction principle. To measure the necessary physical quantities such as force, displacement, velocity, pressure, acceleration, torque, s mutual or self-inductance is varied.

Strain Gauge
A strain gauge displacement transducer is used to change physical quantities like pressure, displacement, or load into mechanical strain, and this mechanical strain is changed into electrical o/p with mounted strain gauges on the elastic body. A strain gauge displacement transducer is mainly used for measuring the displacement in the 0 to 10 mm range. This transducer has a short body length as compared to LVDT & is free from electromagnetic effects. These strain gauge transducers have highly stable & reliable performance.

1. If the electronic ruler has been used for a long time, and the seal is aging, and there are many impurities in it, and the water mixture and oil will seriously affect the contact resistance of the brush, this will cause the displayed number to jump continuously. At this time, it can be said that the electronic scale of the displacement sensor has been damaged and needs to be replaced.

2. If the capacity of the power supply is small, many situations will occur, so the power supply needs to have sufficient capacity. Then, the insufficient capacity will cause the following situations: the movement of the gluewill cause the display of the clamping electronic scale to change, and there will be fluctuations, or the movement of the clamping will cause the display of the electronic scale to fluctuate, causing a large error in the  measurement results. If the driving power of the solenoid valve and the power supply of the displacement sensor are together at the same time, the above situation is more likely to occur. When the situation is serious, the voltage fluctuation of the multimeter can even measure the relevant voltage fluctuation. If the situation is not caused by high frequency interference, static electricity interference or not good enough neutrality, then it may be caused by the power of the power supply being too small.

3. Both FM interference and electrostatic interference may make the digital display of the displacement sensor beating. The signal line of the electronic ruler should be separated from the strong line of the equipment. The electronic ruler must use a grounding bracket compulsorily, and at the same time, the outer surface of the electronic ruler should be in good contact with the ground. The signal wire needs to be shielded, and a section of the electrical box should be grounded to the shield. If there is high frequency interference, the voltage measurement using a multimeter usually shows normal, but the displayed number will be non-stop. When there is electrostatic interference, the situation is the same as high frequency interference. To prove whether it is electrostatic interference, you can use a power cord to short the cap screw of the electronic ruler to some metal on the machine. As long as the short is connected, the electrostatic interference will be eliminated immediately. of. However, if you want to eliminate high frequency interference, it is difficult to use the above method. High frequency interference often occurs in inverter power savers and robot hands, so you can try to stop the high frequency power saver or robot to verify whether it is high. Frequency interference.

4. If the electronic scale of thedisplacement sensor is in the process of working, the displayed data at a certain point will jump regularly, or when no data is displayed, you need to check whether the insulation of the connecting wire is damaged. , And the machine's shell is in regular contact with the ground caused by short circuit.

5. The voltage of the power supply must be stable. The industrial voltage must meet the stability of ± 0.1 [%]. For example, if the reference voltage is 10V, it can allow fluctuations of ± 0.01V. If it is not, it will cause a display The snare fluctuates like this. However, if the amplitude of the displayed fluctuation does not exceed the amplitude of the fluctuation voltage at this time, then the electronic ruler is normal.

6. The alignment of the displacement sensor needs to be very good, but the parallelism can allow an error of ± 0.5mm, and the angle can allow an error of ± . However, if the parallelism error and the angular error are both too large, the display of digital jitter may occur. Then when this happens, the parallelism and angle must be adjusted.

7. In the process of connection, you must pay more attention. The three wires of the electronic ruler cannot be connected wrongly, and the power line and output line cannot be exchanged. If the above lines are connected incorrectly, a large linear error will occur. It will be difficult to control, the control accuracy will become poor, and the display is prone to jumps.

Fault Reason Of Displacement Sensor
There may be many reasons for the failure of the displacement sensor. For different types of displacement sensors, their failure reasons may also be different. Therefore, when using and maintaining the displacement sensor, relevant regulations and guidelines should be followed to ensure its normal operation and effectiveness.
The most common cause is wear or aging. Because displacement sensors usually need to withstand harsh working environments such as high temperature, high pressure, vibration and repeated load, long-term use may lead to wear or aging of internal components of the sensor, thus reducing its measurement accuracy and stability; External damage is also a major cause. Because displacement sensors are usually exposed to the working environment of machinery and equipment, they may be affected by physical impact, impact, pressure and other external factors, resulting in damage or failure of internal components of the sensor; Improper cleaning can also cause machine failure. Because the displacement sensor needs to maintain a dry, clean and dust-free environment, if improper cleaning solution or cleaning method is used during cleaning or maintenance, the sensor element may be damaged or invalid; Because the displacement sensor usually requires external power supply, if the power supply is unstable or the power supply fails, the sensor measurement signal may be abnormal or invalid; The displacement sensor needs to be installed in a suitable location and environment. If the installation location is incorrect or disturbed by the environment, the measurement accuracy and stability of the sensor may be reduced.

Judge the quality of displacement sensor
In order to ensure that the displacement sensor can work with high intensity and accuracy for a long time, we should learn how to judge the quality of the displacement sensor when selecting the displacement sensor.
The first thing to pay attention to is the accuracy of the displacement sensor, which is a very key indicator of the displacement sensor. Generally speaking, the higher the accuracy, the more accurate the data measured by the sensor. Therefore, it is necessary to pay special attention to the accuracy index of the sensor when purchasing the sensor to ensure that it can meet the actual needs.
The sensor needs to maintain high stability during use to ensure the consistency and reliability of the sensor measurement results. Therefore, it is necessary to check the service life, anti-interference ability and other indicators of the sensor to evaluate whether its stability meets the requirements.
In some cases, the sensor is required to have a high response speed, which is also one of the important indicators to evaluate the quality of the sensor. The faster response speed is, the better the real-time performance of the sensor will show.
Some industrial environments are relatively harsh, requiring sensors with high durability to cope with harsh working conditions. When selecting and purchasing sensors, we need to pay attention to the sensor's material, protection grade and other indicators to ensure that the sensor has sufficient durability.
To ensure the quality and after-sales service of the sensor, we need to select well-known position sensor. Select the appropriate displacement sensor according to the actual budget, and do not blindly pursue low prices, otherwise the accuracy and stability of measurement may be affected.