Several factors that affect the work of ultrasonic sensors

Several factors that affect the work of ultrasonic sensors

The following factors may affect the work of ultrasonic sensors. This article is for reference only.

One: range and size

The size of the detected object will affect the maximum effective range of the ultrasonic sensor. The sensor must detect a certain level of sound wave to be excited to output the signal. A large object can reflect most of the sound wave to the sensor, so the sensor can be in its The sensing of this object is maximized, and a small object can only reflect very few sound waves, which significantly reduces the sensing range.

Two: The measured object

The ideal object that can be detected using an ultrasonic sensor should be a large, flat, high-density object that faces the sensor sensing surface vertically. The most difficult to detect are those that are very small in area, or that can absorb sound waves, such as foam, or the corners facing the sensor. Some objects that are difficult to detect can be taught on the background surface of the object before responding to the object placed between the sensor and the background.

For the liquid measurement, the surface that needs the liquid is perpendicular to the ultrasonic sensor. If the liquid surface is very uneven and fluctuates, the response time (St) of the sensor needs to be adjusted longer, and it will average the changes. , can greatly reduce the impact of very uneven, large fluctuations on the measurement results.

Three: Vibration

Both the sensor itself and the surrounding machinery's vibration will affect the accuracy of the distance measurement. In this case, some shock absorption measures may be considered. For example, using rubber anti-vibration equipment to make the sensor a base can reduce the vibration, and the fixed rod can also be used. Eliminate or minimize vibration. Attenuation Temperature-compensated ultrasonic sensors can make adjustments when the ambient temperature changes slowly, but if the temperature changes too quickly, the sensor will not be able to make adjustments.

Four: Misjudgment

Sound waves may be reflected by nearby objects such as guide rails or fixtures. In order to ensure the reliability of detection, the influence of surrounding objects on sound wave reflection must be reduced or eliminated. In order to avoid false detection of surrounding objects, many ultrasonic sensors have a LED indicators are introduced to the operator for installation to ensure that the sensor is properly installed and reduces the risk of errors.

The ultrasonic sensor emits a high-frequency sound pulse that is inaudible to the human ear, and measures the time difference that the signal is emitted to be returned by the object. Robust ultrasonic transducers have successfully demonstrated their superior performance on various occasions, especially for non-contact object measurement or inspection. This can also be used in very harsh working environments. The most impressive performance of people is the material that can accurately detect various materials and colors (not affected by material and color).

Basic principles of using ultrasonic sensors:

The ultrasonic sensor utilizes the vibration of the vibrating ceramic of the sensor head to generate high-frequency (human ear can't hear) sound waves to sense. If this sound wave touches an object to reflect back, the sensor can receive the echo. The sensor can determine the distance between the sensor probe and the object based on the wavelength of the sound wave and the time difference between the transmitted and received echoes. In a typical application, a sensor can have both short-distance and long-distance settings through the setting of a button. The sensor can detect the object regardless of the type of boundary. For example, an ultrasonic sensor can be mounted on a liquid-filled tank or a small ball box and send a sound wave to the container. By receiving the return wave, it can determine whether the container is full, empty, or It is partially full.