What are the working principles and common problems of wind sensor?
Wind sensor mainly include wind speed sensor, wind direction sensor and ultrasonic wind speed and wind direction sensor.
Working principle of wind speed sensor
Wind speed sensor is mainly used to measure the wind speed of the wind sensor. The wind generated by the airflow drives the rotation of the top three wind cups, and the central axis drives the internal sensing element to generate output signals, which can be used to calculate the wind speed.
Working principle of wind direction sensor
Wind direction sensor is a wind sensor used to measure and transmit wind direction information. By rotating the wind direction arrow, it transmits its measurement information to the coaxial encoder board and outputs the relative value of wind direction.
Working principle of ultrasonic wind sensor
The ultrasonic wind sensor calculates the wind speed and direction through the influence of the wind speed component which is parallel to the direction of the propagation of sound waves in the air. The basic components of acoustic anemometer are composed of ultrasonic transmitter and receiver located at both ends of sampling space.
Component of wind sensor
The core sensing part inside the wind direction sensor is the wind blade, and the current wind direction value is calculated by the rotation of the bearing of the wind blade
The sensing part of the wind speed sensor is a three-cup wind component consisting of three carbon fiber wind cups and a cup holder. The converter is a multi-toothed rotor and slit optical coupler. When the wind cup is rotated by the horizontal wind, the frequency signal is output through the rotation of the rotor cup in the active shaft of the slit photocoupling.
The transducer of the wind speed sensor uses a precision conductive plastic potentiometer. When the wind direction changes, the tail rotor drives the potentiometer shaft to rotate through the shaft rotation, so as to produce variable resistance signal output at the active end of the potentiometer.
Wind sensors may encounter some problems in use. The following is the analysis of the reasons for the problems of the wind sensor:
What’s wrong with the wind sensor?
Wind speed sensors problem
Inflexible rotation, stuck
When this happens with a new wind speed sensor, it may be due to loose internal components that cause bearing rotation problems. Measure the wind speed sensors after the device is powered on. If any fault occurs, contact the manufacturer to replace the sensor. Manually rotate the wind cup on top of the wind speed sensors. If the air cup does not rotate smoothly, the device is not properly connected. You can operate under the guidance of technical personnel.
If the old wind speed sensor is not sensitive in the working process, it is necessary to clean the surface of the sensor first to see whether there are obstacles around the wind cup that hinder its rotation. Such as shielding leaves, frosting on wind cups, tilt of sensors, etc. Even a small feather stuck to the wind cup can cause a large deviation in the value.
Secondly, if the above problems are eliminated, the sensor needs to be manually removed to remove dirt and other stolen goods inside. In windy and sandy weather, some fine sand may enter the sensor shaft and affect its work. Therefore, users in the process of using wind speed sensors should be timely maintenance and cleaning, to ensure the service life of equipment. Finally, if the wind speed sensor is used for too long, the internal components are prone to aging or falling off. At this point, the need to replace the wind speed sensor accessories or directly buy a new sensor.
The wind speed is zero
There are three possible reasons for the zero reading of the wind speed sensors. First, the reed switch used as the sensor in the device starts to fail. Tapping the anemometer body above the anemometer shaft sometimes restores correct operation. If possible, tend to identify the reed switch problem, but this is something that will have to be solved sooner or later. Contact professional technical personnel for replacement.
Secondly, another possible cause of intermittent speed readings is cable damage and intermittent contact of speed conductors. Check for problems with the cable and power supply system, connect backup equipment, and rotate the anemometer shaft. If the shaft rotates flexibly and there is no obvious noise, it indicates that the rotating part of the wind speed sensors works normally. Check the readings for data. If yes, check whether other components are normal or there is no data. It indicates that the wind speed sensor is faulty and needs to be replaced.
Finally, if the starting wind speed is too high, the possibility of this reason is relatively small. If you are measuring at a location and the current wind speed is too low, even the starting wind speed of the wind speed sensors cannot be reached, the reading will always be zero. Therefore, to avoid this situation, users should perform measurements at multiple locations and at multiple time points. Measure whether to display the reading under different wind conditions.
There is a significant deviation between the wind speed sensors and other anemometers.
It is not common for users to think that their anemometer readings are insufficient. Several real anemometer problems may cause low-speed readings. The most obvious is that there is a rigid bearing on the wind cup shaft, which can be remedied according to the instructions in the above reasons, or the reed switch is malfunctioning, which may cause the connection with other anemometers. There is a deviation from the reading.
The measurement speed of wind speed will vary with height. Therefore, the two wind speed sensors mounted should be at the same height and the same exposure. Besides, there is another less obvious reason. The wind does not blow at a steady speed, especially in the inland areas, but it usually blows with short highs and lows during gusts.
Most wind speed sensor manufacturers on the market have different equipment measurement principles, and the wind speed ranges measured by different equipment are also very different, so the measured values between different equipment are not comparable.
The indirect reading problem of the wind speed sensors
If it is the wind sensor with Modbus output, the cause of the fault is that the wiring is not connected properly, and the circuit problem needs to be checked.
The cause of the failure of the 4-20ma wind speed sensor may be the unstable connection of the terminal device or a problem with the connection line.
The reason for the failure of the network wind speed sensors is that the current network environment is unstable, the signal transmission is interrupted, and the signal is unstable.
Wind direction sensors problem
The wind vane is not flexible and stuck
If you buy a new wind direction sensor, the wind vane element on the top of the wind vane component is stuck when you manually rotate it, which means that the sensor is damaged and the bearing rotation is obstructed. Contact the manufacturer for replacement. If you connect the device and measure the wind direction sensor with electricity, and the wind vane is not sensitive, you need to replace the sensor or contact the manufacturer to troubleshoot. If you are not an expert in wind direction sensors, it is recommended that you do not disassemble the sensors at will.
If your wind direction sensor is inflexible and stuck after a long time of use, the possible reason is that the internal components have been aging or severely worn due to the long period of maintenance and cleaning. You need to replace the sensor element or disassemble the sensor for internal cleaning.
Wind direction readings intermittently
When the wind direction sensor is put into use, there is a problem with intermittent readings. At this time, you need to check your wiring problems. In most cases, this is caused by poor contact between your equipment and the acquisition device. Professional technicians call it “signal open circuit”.
Incidentally. What is an open signal?
Open circuit refers to the state of the circuit when no current flows between two points in the circuit or a conductor with a very large impedance (or resistance) are connected. An open signal line may be interfered with and produce incorrect output.
In this case, you need to check the connectors and wires patiently.
The wind direction value is zero
Some users will encounter such a problem when they use the wind direction sensors for the first time. When you connect the sensor, the value is always displayed as zero. When encountering this kind of problem, you manually turn the wind vane off the wind direction sensors. If the value changes, it means that the direction where you placed the wind vane coincides with the current wind direction, and the reading is the current wind direction value displayed. If the wind direction value still shows zero during the rotation, you need to check the cable and the power supply system to eliminate wiring problems and no power supply problems. If there is no problem with the above, the internal sensor may be damaged and you need to replace the accessories or sensor.
The azimuth value of the wind direction is incorrect
First of all, the wind direction sensor has a directional sign “N”. During the installation process, the directional sign “N” should point to the true north. If you do not follow this procedure, the problem of inaccurate wind direction measurement will occur.
Secondly, use the backup device to connect and turn the wind vane. If it can be turned so that the wind direction indicator value is 239°, then the wind direction sensor is working properly. Check whether the other parts are working properly; use the backup device to connect and rotate the wind vane, and the wind direction indicator does not appear. 239° and other directions often show jump display, which means that some infrared light-emitting diodes in the wind direction sensor are broken, check and repair; use a wind direction and speed calibrator to check whether the wind direction sensor is working properly.