Proximity or Motion SensorProximity detectors are a valuable tool for home, business, and industrial use. But what do these sensors do? How do they work? Keep reading to discover everything you need to know about proximity sensors and when you can use them. 

What are proximity sensors used for?

Proximity sensors determine if there are objects within a specific area. Some sensors are more detailed and measure how many, how large, or far away these objects are. Short-range sensors are used in industrial settings to count products or monitor object status. Meanwhile, long-range sensors monitor security and environmental conditions. 

How do proximity sensors work?

Each type of sensor works a little differently. However, sensors have one significant thing in common: they don’t rely on physical contact to tell where something is. Instead, these sensors use other physics tricks to identify when something is nearby. 

There are two main methods proximity sensors use. One camp of sensors relies on electricity or magnets to judge whether objects are nearby. These sensors measure how their electromagnetic field is being affected by the surrounding world to determine if something is in range. 

The other relies on reflection and reception. They emit energy and wait to see if and when it’s reflected to the sensor.

How accurate are proximity sensors?

Different types of sensors have varying levels of accuracy. The accuracy involved will also vary depending on how you want to use your detector. High-accuracy sensors can be exact. A light- or ultrasound-based proximity can be accurate to the millimeter over long distances if needed.

What are the types of proximity sensors, and when are they used‌?

There are many types of sensors, but some are more common than others. There are five main types of sensors commonly used in business, industry, and home scenarios. These sensors are:

Inductive Proximity Sensor: These sensors use the electric principle of inductance to detect metallic objects based on how they conduct electricity. They are most commonly used in industrial capacities to count products and in security to detect metal objects. An example is a car alarm proximity sensor that goes off when someone gets too close.

Capacitive Proximity Sensor: These sensors can detect objects by noticing how they affect their electrical charge. They are commonly used in industrial settings to check things like whether products are built correctly. Inductive and capacitive sensors have relatively short ranges. This is also the type of proximity sensor iPhones use to turn the screen on and off.

Magnetic Proximity Sensor: A magnetic sensor can only detect magnetic objects by measuring how magnetic fields around the sensor change. Magnetic sensors have a much more extensive range than inductive sensors. Because of this extended scope, they are often used in industrial settings for which inductive sensors don’t have enough coverage. 

Ultrasonic Proximity Sensor: Ultrasonic sensors rely on sound waves to detect proximity. They bounce sound waves off objects and measure how quickly they return. Ultrasonic sensors are often used to monitor automated processes or detect proximity in extreme conditions like very hot and cold locations. 

Photoelectric (Optical) Proximity Sensor: Optical sensors rely on light to judge how far away objects are. They typically emit infrared (IR) light or lasers and record how the light changes. Reflective sensors monitor how light bounces off objects. They use through-beam sensors to monitor how things break a laser beam. Retroreflective sensors combine the two. Optical sensors have very long ranges and can be used in many conditions. They work great as car proximity sensors. 

Do I have to calibrate or reset a proximity sensor?

Yes, if moved, you typically need to calibrate sensors and reset them. Every sensor has its own calibration settings. You can learn how to calibrate or reset sensors by reading the manual that came with the sensor. Typically, it’s as simple as realigning the sensor with your target area. Then you perform a few test measurements to give the sensor a new baseline reading. 

Where can I buy proximity sensors?

You can buy sensors from Novotech that suit your specific needs. For example, you might want to make sure products are assembled appropriately or that employees are at their desks. To do that, you can replace IFM proximity sensors with better alternatives from Novotech that will monitor things for you. 

How are proximity sensors different from other components?

Sensors are their own unique component. Here’s how they’re different from other types of technology.

  • Proximity sensor vs. proximity switch: A proximity switch uses a sensor to judge when something is nearby. It sends “No” signals until the sensor registers something close enough to switch to “Yes.”
  • Proximity sensor vs. proximity transducer: Transducers convert one type of energy into another in sensors. They convert magnetic energy into electronic signals to alert that something is present. 
  • Proximity sensor vs. proximity transmitter: Sensors monitor whether something is nearby. A transmitter communicates that information from the sensor to the device that will record it.
  • Proximity sensor vs. transducer vs. transmitter: The sensor picks up the proximity of an object. The transducer then converts that information into an electronic form, and the transmitter sends the electronic data to the receiver.
  • Proximity sensor vs. force sensor: A proximity sensor detects whether objects are nearby without touching them. A force sensor touches things to measure how much force or pressure they exert on those items.
  • Proximity sensor vs. proximity gauge: Many sensors run data through proximity gauges, which measure how close the object is instead of whether it’s simply present.
  • Proximity sensor vs. ultrasonic sensor: An ultrasonic sensor is a specific type of sensor that uses ultrasonic sound waves. 
  • Proximity sensor vs. load cell: A load cell is a transducer that converts force into electrical output. Load cells are connected to force sensors but never to proximity sensors. 

What are the applications of proximity sensors in IoT?

A proximity sensor can be used to accomplish many things in IoT. For example, tire, oil, and fuel sensors are critical sensors in:

  • Home use: How much gas is left in your car, and how much air is in the tires? With a sensor, Android and iPhone apps can let you know how your vehicle is doing. 
  • Industrial applications: Are products being built on time? A proximity detector can help you count how many products roll off the line automatically. 

Small business: Are people sitting at their desks? A Bluetooth proximity sensor Arduino can alert you if staff leave their desks too long.