Technical Blog

Common problems with sensors – and how to overcome them

At Positek we are position sensor experts. We have been designing and manufacturing position sensors for over 30 years.

We are often met with customers presented with problems when it comes to position sensors, this guide will discuss some of the most common issues and what we would recommend.

What are the common problems which can occur with sensors and what can we do to overcome them?

Choice of the Type of Sensor

Some of the most common sensor problems we find are down to the initial choice of sensor – without knowing what else is available on the market, many people choose the same sensors over and over again, replacing faulty or worn-out ones with the same model.  It is worth shopping around to find a sensor that is designed to overcome problems that regularly arise, and to ensure that the sensor of choice is the best one for the job, not just simply replacing the one that has always been used because it's the one that is always used!

Application Conditions

When selecting a sensor, it is always good practice to have a list of the conditions in which the sensor has to operate and the range of measurement required.  Using this set of criteria it is possible to eliminate certain sensors from the running; so only the ones that can withstand high temperature or submersion are left as potential options. 

Dust, other contaminants, vibrations, shocks and exposure to high temperatures all have a shortening effect on the average lifespan of a sensor, so it is important to look for a solution that overcomes these problems by design, rather than just accepting frequent sensor failure and replacement as part and parcel of using position sensors.  It is also worth looking at the physical location of the sensor and checking whether environmental effects can be minimized by moving the sensor.

Sensor Technology

Sometimes, it may be the case that traditional sensor technology is not the most suitable way of detecting location or movement, and newer types of sensor, such as RFID, are more suited to the needs of a particular business; warehouse tracking being a good example of where newer developments could perform better than older technologies. 

Mounting Style

 The mounting style of the sensor can also cause problems with detection, as sensors that detect the presence of a particular metal should not be mounted on that type of metal without a free zone between the sensing face and the metal it is mounted on.  Incorrect mounting leads to false detection readings and sometimes this simple factor is overlooked, leading to a lengthy process of trying different sensors when all that is needed is a tweak to the mount. 

Construction Material

 The material that a sensor needs to detect also plays a part in the right sensor choice and is a factor that is often overlooked.  Detecting aluminium (a non-ferrous material) with a sensor, results in short sensing distances whereas detecting the presence of a ferrous material will occur at a longer distance.  The materials around the sensor, as well as those it is expected to detect, is a vital factor to think about when choosing the right sensor, otherwise, the sensor may end up detecting things it is not supposed to.

Pollution and Contamination

 Another common problem with position sensors is the susceptibility to pollution and contamination on the sensing face.  If the sensor relies on positive contact between two switches and there is any matter in the way (even a scrap of paper or dust) then sensing can fail.  

Again this does come down to carefully thinking about the environment in which the sensor will operate, but more specifically about the likelihood of anything getting in the way of the sensor.  

You may choose a sensor that perfectly withstands the heat present in a particular environment, but if the chosen system relies on contact and there is also a high chance of anything blocking the sensor (in a paper mill, for example) then the sensor choice needs to be reconsidered.

Conclusion

So we can see that many of the common problems with position sensors are down to an incorrect choice, to begin with – expecting a sensor to perform in an environment it is not designed for.  By carefully selecting the right position sensor or having a custom system built, most of these issues can be eliminated, resulting in lower long-term sensor costs, less replacement activity, and less unintended downtime.  

Position Sensors from Positek

At Positek we have a range of position sensors suitable to a whole host of underwater, intrinsically safe and industrial environments. We also have an on-site design facility so custom sensors can be designed and built to your requirements.

Contact Positek today to see how we can help you find the right one.

Article published on: 21/02/2022