Ultrasonic fuel consumption sensor

- Apr 09, 2018-

The ultrasonic fuel consumption sensor adopts an external mounting type and is bonded to the central position of the bottom surface of the box. The ultrasonic ceramic wafer layer in the sensor is driven by an external excitation source, and the time difference of the mechanical wave reflected by the original mechanical wave and the received liquid interface is used. , Combining ultrasonic sound speed to achieve a preliminary measurement of the liquid level in the tank.


The ultrasonic fuel consumption sensor adopts an external mounting type and is bonded to the central position of the bottom surface of the box. The ultrasonic ceramic wafer layer in the sensor is driven by an external excitation source, and the time difference of the mechanical wave reflected by the original mechanical wave and the received liquid interface is used. , Combining ultrasonic sound speed to achieve a preliminary measurement of the liquid level in the tank, such as the measurement diagram. The sensor has a wide range of applicability, sound guidance with gaseous media, liquid media or solid media, low price, no pollution and relatively easy signal processing, so the ultrasonic fuel consumption sensor will become an important peripheral accessory of the vehicle-mounted monitoring system.


A narrow pulse of intermediate frequency generated by a 32-bit Cortex M3 processing chip acts on the excitation circuit, generating a mid-range pulse voltage of a few hundred volts to induce deformation of the ceramic wafer, which in turn generates a mechanical wave for detection. The mechanical wave propagates in the medium and reflects and refracts at the interface between two different media. There are a total of four interfaces at the time of detection. The first layer is the interface between the protective layer of the probe and the adhesive layer (adhesive between the probe and the fuel tank). Through the adhesive layer into the second layer, the second layer is the outer wall of the adhesive layer and the fuel tank, through the outer wall layer into the third layer, the third layer is the bottom surface of the liquid inside the tank and the bottom surface of the tank, wear The liquid in the oil tank touches the fourth floor. The fourth floor is the interface between the liquid and air in the tank. Reflection occurs along the original path, and the returned mechanical wave resonates with the ceramic wafer 2 to generate a sinusoidal voltage signal from microvolts to millivolts. The signal is processed by an intermediate-frequency small-signal tunable amplification detector and a 32-bit CortexM3 processing chip. The height of the liquid = speed of sound in the medium*time/2+environmental factor"calculates the height of the liquid level.