Working principle of ultrasonic ranging and temperature measurement

The working principle of ultrasonic ranging and temperature measurement is: ultrasonic digital ranging is to use ultrasonic emission, and the time difference after receiving the reflected echo of the measured object is used to measure the measured distance. It is a non-contact measuring instrument. Because the propagation speed of ultrasonic waves in the atmosphere is related to the temperature, such as 331.36 meters per second at 0 degrees Celsius and 343.38 meters per second at 20 degrees Celsius. Therefore, the ranging and temperature measurement controller uses the temperature sensor DS18B20, and sends the signal that changes with the ambient temperature to the single-chip microcomputer. The MCU reads the value of the external temperature change and performs internal calculations, and corrects the error value of the ranging under various ambient temperatures. This function is used to conveniently realize the temperature measurement display.

The ultrasonic distance meter utilizes the propagation characteristics of ultrasonic waves in the air. It has many characteristics such as: no contact with the measured object when measuring the level distance, no moving parts, simple installation and debugging, no maintenance, convenient maintenance, high measurement accuracy, as a level measurement controller. It measures and controls the precise position of material level and liquid level changes, so it can non-contactly measure various corrosive liquids and solids. Through the preset input of the controller keyboard to open or close the distance control value, the automatic control of the material level and liquid level can be realized, and 1200BIT serial data signals can be output for connection with PC computers and remote display panels. For example, the 485 standard serial port can transmit more than 2000 meters, which is conducive to the remote transmission and processing of data.

The distance measuring level controller has a simple circuit and can replace tape measures and rulers to measure and control the water level of water towers and the reversing display of various vehicles. It can send out different alarm signals according to the values ​​of the detected objects and the changes in the ultrasonic probe to achieve automatic control.