Ultrasonic Vs Infrared (IR) Sensors
Your choice of a sensor in your application can be challenging for any project. The performance of your system depends greatly on the reliability of your sensor and other components of the application.
In order to determine the right sensor for your application, there are things that need to be taken into consideration for sensor selections.
- Accuracy – How close the reading is to the true distance.
- Resolution – The smallest reading or change in readings that can be reported.
- Precision – The smallest reading that can be taken repeatedly and reliably.
Ultrasonic vs Infrared – How do they work?
How Ultrasonic Sensors Work
Ultrasonic sensors work on the principle of reflected sound waves and are used to measure distance. One sensor can detect others operating nearby. Sound waves are emitted by the ultrasonic sensor and they’re reflected back if there is an object in front of it. The sensor detects these waves and measures the time it takes between transmitting and receiving those sound waves. Distance is then estimated by the time interval between sensor and object.
Basic Sonar Illustration – A transducer generates a sound pulse and then listens to the echo.
Ultrasonic sensors are, for the most part, completely insensitive to hindering factors like:
Ultrasonics aren’t as good as Infrared at defining edges of an area.
The ultrasonic sensors are used for liquid level measurement, object detection, distance measurement, anti-collision detection and pallet detection among others. Ultrasonic sensors are used to improve the operational efficiency and provide additional safety in manufacturing facilities. This is one of the major factors fueling the demand for ultrasonic sensors globally.
How Infrared (IR) Sensors Work
Infrared sensors work on the principle of reflected light waves. Infrared light reflected from objects or sent from an infrared remote or beacon. Infrared sensors are also used to measure distance or proximity. The reflected light is detected and then an estimate of distance is calculated between sensor and object.
Infrared sensors can’t work in dark environments while Ultrasonic Sensors can.
Brighter surfaces are easier to detect for Infrared than dark surfaces, as the sensor doesn’t detect darker surfaces. Infrared sensor values normally fluctuate in variant light conditions.
When objects pass within the range, the light waves detect those objects and reflect the presence back to the sensor. Their wavelengths are less than that of microwaves. While they’re able to detect motion, they can also measure the emission of heat by an object.
Peter Alaric from Lyratron shows how different it is using an IR sensor versus using an Ultrasonic sensor in his AirHarp project.
In Conclusion of Ultrasonic vs Infrared
Choosing your sensor is completely dependant upon your application. There are a lot of limitations in infrared sensors, like the inability to use them in sunlight due to interference. It can make outdoor applications or dark indoor applications very difficult. Ultrasonic sensors work using sound waves, detecting obstacles is not affected by as many factors. If reliability is an important factor in your sensor selection, ultrasonic sensors are more reliable than IR sensors. If you’re willing to compromise reliability for cost, infrared sensors are ideal for your application.
Who do you prefer in the battle of ultrasonic vs infrared?
What type of project are you building?
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A Few of Our Most Popular Products
Features of the MB1000, LV-MaxSonar-EZ0, include one-inch resolution, the widest and most sensitive beam pattern of any unit from the LV‑MaxSonar‑EZ sensor line, range information from 6 inches to 254 inches, a 20Hz read rate, and various output options: pulse-width, analog voltage, and RS232 serial.
Features of the weather resistant MB7092, XL-MaxSonar-WRMA1, include small target rejection providing range information to the target with the largest acoustic return, a stability filter, centimeter resolution, range information from 20cm to 765cm, a 10Hz read rate, and various output options: analog envelope, analog voltage, and RS232 serial.
Features of the MB1403, HRUSB-MaxSonar-EZ0, include millimeter resolution, the widest and most sensitive beam pattern of any unit from the HRUSB‑MaxSonar‑EZ sensor line, range information from 300mm to 5000mm, a ~4Hz read rate, and a USB serial output.