Manufacturing | Sensors

Sensors in Smart Manufacturing – Why they’re vital

Words by Alex Matheson
Sensors in Smart Manufacturing – Why they’re vital

Smart manufacturing is a broad term and the equipment and expertise needed to realise it are varied. One person’s concept of it may be archaic to another person, or they may be a science fiction fever dream. However you choose to define it though, you’re going to need sensors to achieve it.

Of all the potential technologies that go into the factory of the future, sensors are one that you can’t get away from. Industry 4.0 is typified by the blurring of lines between the physical and digital world, and the digital part needs eyes, ears, and other mechanical sensory organs; enter sensors.

How do sensors work?

Sensors convert physical stimuli into electrical signals. These electrical signals can be sent to processing units where the electrical signals can be converted into data.

If you consider the human eye – light rays enter the eye and hit the retina which converts those light rays into neural signals. Those signals travel down the optic nerve to the brain where the brain interprets them. In this way, we can view the world and convert light into information.

Sensors in manufacturing take in signals in a similar way. They register temperature, movement, light, physical dimensions, and other types of signal. They transmit those signals to a computer or a central processing unit (CPU), where they are turned into data.

What type of sensors are used in manufacturing?

There’s a sensor out there for pretty much anything you might want to measure throughout a manufacturing process. Some of them are general use and can be adapted to multiple different situations, some of them are custom made and very specific.


Starting simple we’ll look at something most people likely have in their own home. A thermometer measures temperature and is incredibly useful. Whether it’s measuring the temperature of a product, a machine or even an environment within a manufacturing system.

It could help in predictive maintenance, for example ensuring that when a machine gets too then a maintenance engineer is instructed to come and inspect it. Or, it might let a welding machine know when a bonding agent has reached the right temperature for application.

Image sensors

These really are the eyes of the mechanical world. They might have had limited utility in the past, really only relaying information for people to review, but with machine learning and AI, they fit right into the factory of the future.

By teaching computers what different elements within a picture could mean, intelligent systems in manufacturing can carry out evaluative operations. We’re still developing applications smart enough to properly evaluate images, but they’re becoming more and more useful in manufacturing.

Motion sensors

Motion sensors might be set up to spot a type of motion or any motion at all. They can be used to count items passing a gate, or used to alert maintenance systems when a piece of equipment is moving how it shouldn’t.

Motion sensors could also be stationary or exist in motion, as it were. Gesture recognition facilitated by motion sensors can enable things like the tracking of hand movements in virtual or augmented reality.

Vibration sensors

Similar to motion sensors but with very specific focus and application. Often vibration sensors fill a safety role, advising of unsafe or anomalous vibrations in industrial situations. With vibration sensors, machines can detect minute warning signs that a human can easily miss.

Level sensors

Another one we probably all have in our homes, or at least our vehicles, but probably not one we give much thought. Level sensors can use a variety of means to measure the level of a given material, for example how much petrol you have in your petrol tank.

In the digital world of smart manufacturing, level sensors could be integrated into your inventory and ordering systems, ensuring you’re never without what you need or overstocked on ingredients.

How do sensors communicate in manufacturing?

Sensors are great but if they can’t relay the information they collect, they’re no use at all. In the earliest days of manufacturing, sensors would need to be checked manually by workers. Gauges, readouts, and other visual representations of data would need to be checked to record everything from temperature to pressure.

As technology progressed, sensors could be wired up and linked into systems built specifically to monitor the information relayed by sensors within a manufacturing environment.

With the advent of wireless technologies, sensors could transmit their data without needing to be physically connected to the systems they were talking to. By introducing 5G networking, we’re beginning to realise actual real time communications between manufacturing systems, not just locally, but globally.

Output, efficiency and maintenance levels can now be monitored not just from a single location within a facility, but from a single location at the centre of multiple networked smart facilities. This means expertise and excellence isn’t limited to the people geographically close to a manufacturing centre, but can be drawn from the world at large.

With sensors able to communicate wirelessly, you enter the world of the internet of things (IoT) and the industrial internet of things (IIoT). Systems communicating with each other means maintenance can be monitored automatically, stock levels assessed without human involvement, and many other networked marvels take place.

The factory of the future can truly take shape.

How are sensors used in smart manufacturing

We could list types of sensors all day, but there’s too many to cover in just one article. What’s more important is how these sensors can be used. When you can measure virtually anything, how do you make sense of that data and turn it into insight?

Predictive maintenance

We’ve written a whole article on predictive maintenance, but in brief, it’s one of the most important things the factory of the future has to offer. Limiting down time by only conducting maintenance when it’s needed, and knowing when that is before it’s too late; that’s impressive.

But to facilitate this, you need sensors. Your equipment can’t tell your maintenance systems it might need a once over if there’s nothing keeping a digital eye on things.

Data led decision making

Sensors can track how much product you’re making, how many defects are being produced, how many raw ingredients are being used, all in real time. Mass production means massive amounts of data and sensors can collect it as it’s being produced.

You’ll need systems capable of turning that data into insight, but those systems need data to crunch in the first place. That’s where sensors shine.

Compliance excellence

Sensors don’t just collect information you can use for business intelligence, they can harvest compliance data as well. Regardless of where the regulations are coming from, you’ll need to be able to provide accurate and complete data sets to ensure you meet compliance and sensors allow you to do that automatically.

Can you achieve smart manufacturing without sensors?

No. In fact, with the advances we’ve made in the last decades and centuries, it’s almost impossible to achieve non-smart manufacturing without sensors! Even the humble thermometer is a vital piece of sensory equipment in almost all manufacturing circumstances.

Smart manufacturing might rely on big brains, or in this case powerful computers, but those brains need information and data to achieve the things they’re capable of. Without sensors, they’re unable to sense the manufacturing world they’re designed to revolutionise.