Understanding Ultrasonic Sensors and their Components

For a device so important in manufacturing processes, a lot of people still don’t know or rather appreciate the relevance of sensors. They are a part of nearly every machine or electrical product. Since their creation, they’ve become increasingly relevant in various manufacturing processes and in the manufacturing industry.

In most devices or machines, they are not readily seen because they are tiny and are often concealed from view to protect them from damages. Their application is widespread and encompasses several industries. Sensors are crucial pieces in automation like automatic lights, doors, and windows, and safety devices like fire and smoke detectors, to mention a few.

While the above-mentioned applications may not sound impressive, when you carefully consider the convenience that we enjoy through automation, you may begin to appreciate these little devices more. Other uses include self-driving cars, security, and monitoring system. In manufacturing plants and factories, you’ll find even more complex applications like the prediction of equipment failure, an automatic trigger of maintenance protocols, detection of system failures that can affect product quality, and so on.

Since sensors can receive and process information quickly, production processes can be sped up with even greater efficiency. Therefore, manufacturing industries are investing heavily in sensor-installed machinery and technology.

What is a Sensor?

A sensor is a device that detects the changes in a specified quantity (e.g., light intensity, temperature, pressure, etc.) and converts this change into an output, usually an electrical or optical signal that can be further processed. There are different types of sensors and can be classified by the following:

• Mode of detection
• Analog and digital
• Conversion phenomenal
• Passive and active.

They can also be classified based on the quantity or parameter they detect. Examples include pressure, touch, light, temperature, chemical, proximity, tilt, GPS, Infrared (IR), fingerprint, ultrasonic, Lidar, current, humidity, sound, accelerometer, metal, vibration, and magnetic sensors. Click here to learn more about Lidar sensors.

Application of Sensors

Like we mentioned earlier, these devices are used in nearly every functional system or electronics in the world today. Below are some of the areas in which this technology is being heavily applied:

• Embedded systems
• Robotics
• Automation
• Smartphones
• Smart cars
• Smart homes
• Smartwatches
• Computers
• Remote sensing
• Energy plants
• Communications
• Avionics, and much more.

What are Ultrasonic Sensors?

Ultrasonic sensors are one of the most popular types of sensors. They have a wide range of applications which is why they are frequently used by manufacturers. Like many products of technology, the invention of ultrasonic sensors was inspired by one of nature’s creations, the bat.

Bats are partially blind creatures that interact with their environment by emitting sound waves that are reflected by the objects around them. Their brain then processes the reflected wave and makes sense of them. This is how bats are able to locate food and avoid obstacles as they fly.

An Ultrasonic sensor functions by following this exact principle. These sensors were created to measure the distance of objects. To do this, they emit ultrasonic waves that travel until they hit the target object. Once an impact is made with the object, the wave is reflected, traveling back to its source, the sensor.

When the sensor receives the reflected wave, it is able to measure the distance between itself and the object by calculating the time taken for the wave to travel to and from the object. This process is swift and accurate and can be efficiently used to measure object distance.

Following the process described above, we can conclude that the longer it takes for the wave to travel to and from the object, the farther away the object is from the sensor. A rather simple concept. Ultrasonic products are becoming increasingly more available to customers, thanks to some tech companies that have made this possible. You may want to check out SensComp to see how some of these companies are finding new ways that sensors can be utilized.

Components of an Ultrasonic Sensor

Ultrasonic sensors are made up of several functional components including:

• A transmitter
• A receiver
• Transceiver

Transmitter

A transmitter is the part of the sensor that converts small signals into more usable ones. They convert very small electrical signals like milliamps (mA), millivolts (mA), microvolts (µV), or frequency into larger current signals or voltage like 4-20 mA or 0-10 volts. Transmitters generally use devices such as operational amplifiers (op amps) to linearize and amplify the output signal.

Receiver

A receiver is the part of the sensor that receives the reflected wave or signal, which is then processed to determine the distance of the object.

Transceiver

As you may have guessed from its name, a transmitter is the combination of a transmitter and a receiver. Some sensors have a transceiver instead of single transmitters and receivers. A transceiver can be any of the two modes transceivers come in. These are the half-duplex and full-duplex modes.

Transceivers that are of the half-duplex mode are unable to transmit signals while receiving signals and vice versa. Full-duplex mode transceivers, on the other hand, are designed to support transmission during reception periods. Transmission and reception in transceivers are often done on the same frequency.

Advantages and Disadvantages of Ultrasonic Sensors

Advantages

1. Ultrasonic sensors are very reliable and produce consistent results.
2. They have flexible minimum and maximum ranges, and most can detect objects as close as a few centimeters and objects as far as five meters away. Specially configured sensors can measure nearly 20 meters.
3. They are resistant to electrical and most acoustic noises.
4. They can make several measurements per second, which results in quick refresh rates.
5. Ultrasonic Sensors are relatively affordable.
6. Their functionality and accuracy are not affected by the color of the object, including transparent or translucent objects like glass or water.
7. Results are relatively precise.

Disadvantages

1. Like other types of sensors, their functionality can be affected if they get wet, frozen, or dirty.
2. Because they rely on sound, they cannot function in a vacuum.
3. Environmental conditions may affect the precision of measurements since the speed of sound can be influenced by temperature and humidity.
4. While they are generally regarded as being small and can be seamlessly integrated into most industrial applications, these sensors hardly fit into smaller projects.

Final Thoughts

Ultrasonic sensors have a wide range of industrial applications. However, the most common use of these devices is liquid-level sensing. Other applications involve general object detection as we see in self-driving cars and automatic vacuum cleaners.