When industries want to detect levels and sense proximity with high precision, they use ultrasonic sensing. If you are wondering how it works, this guide aims at introducing you to ultrasonic sensors and the principle behind the technology. You will also find out how to apply it in your business.
As with all technologies, there will be benefits as well as limitations. We will include this information so you can decide whether it’s something you would like to use or not. For a start, let’s find out what ultrasonic sensors are.
What Are Ultrasonic Sensors?
They are electronic devices that measure the distance of target objects through the emission of ultrasonic sound waves and convert the sound into electrical signals. Ultrasonic waves move faster than audible sound. The devices have two major components:
A transmitter that emits sound with the aid of piezoelectric crystals.
A receiver that collects the sound that reached the target and came back to the device.
The Working Principle of Ultrasonic Sensors
The principle behind ultrasonic sensors is very simple. The electronic devices send out sound waves at frequencies that are higher than the normal hearing range for humans. A transducer inside the sensor receives and sends the sound just like a microphone.
The sensor measures when the sound was sent and when it was received to determine the target’s distance. You can read this article to get a detailed explanation of how the sensors work.
Applications of Ultrasonic Sensors
Ultrasonic sensor solutions are very useful in detecting clear objects. A machine that uses an infrared sensor may struggle to measure liquid levels because the target is translucent. However, ultrasonic sensors can detect presence irrespective of material, surface, or color.
There are five standard applications of ultrasonic sensing. They are:
1. Object Detection
Many tech companies and auto manufacturers are developing completely autonomous and self-driven cars. Both human and self-driven vehicles incorporate driving assistance technology by using sensors to extensively monitor roads as well as surrounding conditions. These sensors detect vehicles in adjacent positions and alert drivers if the vehicles are in blind spots.
2. Distance Detection
The sensors help drivers to avoid colliding with other vehicles or objects behind or in front of their own vehicles. They are particularly useful when parking as they monitor the proximity of vehicles to walls or other objects, and then alert the drivers to stop. They also work well in traffic because they still function accurately when in motion.
3. Diameter Detection
This is used mostly in factories. The sensors ensure that automated lines of production move smoothly. An example is a printing facility where magazines and newspapers are produced. Typically, the paper comes in rolls and as they are used, the diameter of the rolls diminishes.
The sensors can help the printing facility detect when the rolls are running out. This will ensure that they are ready to insert fresh rolls before the printing line is interrupted. These sensors also work with materials that absorb sound like wadding or rubber.
4. Sag Detection
The sensors ensure that cables, conveyor belts, or wires used in manufacturing and other industrial settings are properly positioned. When cables sag, production lines may stop abruptly or become slow. Hence, the sensors can detect when the cables need tightening.
They can also detect minute faults or flaws, which make them incredibly precise. And during manufacturing, dust particles cannot affect their ability to sense objects.
5. Level Detection
This applies to food industries where food items can be produced continuously instead of in batches. For instance, in the production of cheese, sensors help creameries to monitor the levels of rennet and milk in coagulator machines. That way, they know when to resupply more ingredients to ensure continuous production.
More uses include:
Counting bottles on machines that fill drinks
Helping forklifts to detect pallets
Controlling trash assembly and collection
Sorting boxes using multi-transducing ultrasonic monitoring devices
Detecting people for counting purposes
Profiling or contouring
Detecting cars in an automotive assembly or car wash
Unwind and winding and tension control
Wire or thread break detection
Controlling stacking height
Detection of irregular parts in feeder bowls and hoppers
Detection of inkwell level
Advantages and Limitations of an Ultrasonic Sensor
Ultrasonic sensing is useful in many areas, but you need to understand its limitations as well.
It reflects sound off objects. Therefore, the transparency or color of an object does not affect its reading.
Unlike a proximity sensor, dark environments do not affect its detection ability.
It is not expensive and suits specific needs.
Some products are self-cleaning such that extreme exposure to dirt, moisture, and dust does not affect them.
It is not difficult to use and isn’t dangerous when close to equipment, objects, or people.
It measures the distance to parallel surfaces and thickness at greater accuracy compared to other methods. You can check out SensComp sensor solutions to learn more about the advantages of using ultrasonic sensing.
It can’t function in a vacuum because it operates using sound. The sound waves need air to travel, which is absent in a vacuum.
It is not suitable for underwater uses.
Objects that are covered in soft fabrics absorb a lot of sound waves. This makes it difficult for the device to detect the target.
A change in temperature, within 5 to 10 degrees or more may affect its sensing accuracy. However, there are some temperature compensated sensing devices that can calibrate before or upon commencement of a range reading. This allows the device to calibrate with changes in voltage or temperature.
The detection range is quite limited. Some products have a max range of ten meters. Although this is a limitation in some applications, it can suit many other applications.
Although there are different types of sensors in the market, ultrasonic sensors are more reliable. They also offer a high level of precision when detecting objects and are hardly affected by environmental conditions such as light, moisture, dirt, and dust. They have a wide range of applications that everyone can benefit from. The technology may have some limitations but its benefits far outweigh them.