How To Avoid The Five Most Common Sensor Malfunctions

Sensors Insights by Kayla Matthews

When sensors work as expected, people hardly notice them and only pay attention to the advantages that wouldn't be possible without such components. However, malfunctions can still occur. When they do, the effects can cause customers to lose trust in a brand and determine that their investments were not worth the money. Here are five of the most common ways sensors can fail, and how to avoid those faults.


1. Incorrect Readings Due to Improper Mounting

Many people go through upsetting trial-and-error processes while trying to get sensors to work. The issues they run into are often due to the assumption that the problem is happening because of the sensor itself, such as an issue with the internal wiring.

However, abnormal readings can also occur because of incorrect mounting. For example, a sensor that detects the presence of metal cannot be attached to that same kind of metal unless a free zone exists between the mounting surface and the metal the sensor recognizes. Otherwise, incorrect readings may result, and the easiest way to prevent them is to change the mounting position or surface.


2. Calibration Drift in Pressure Sensors

Food and beverage companies commonly use pressure sensors in factories to maintain regulatory and quality standards. However, if condensation builds up on the sensor, it can cause a calibration "drift."  When that happens, people who are operating the equipment with pressure sensors may not know anything has gone wrong. Sometimes, a lack of calibration causes processes to shut down.

In an environment where maintaining instrument calibration is imperative, many clients select pressure sensors that are less likely to experience drift than others. Engineers may also implement venting systems that promote airflow to prevent condensation from becoming problematic.


3. Printed Circuit Board (PCB) Issues

Printed circuit boards (PCB) are part of many of the most popular gadgets, ranging from smartphones to IoT devices. However, numerous issues can arise if manufacturers and designers don't take care to avoid problems with a PCB and any surrounding sensors. For a start, it's best to avoid 90-degree angles for most components because they tend to increase electromagnetic interference (EMI). Excessive amounts of EMI can lead to a defective product.

Moreover, using a design for manufacturing (DFM) helps PCB makers avoid problems that could otherwise crop up during the production process. A DFM check involves inspecting a PCB layout for possible shortcomings that could disrupt the fabrication and assembly processes. When you're making an Internet of Things (IoT) device with several sensors, for example, remember that it's necessary to check for hotspots and assess whether temperature changes could disrupt the sensors.


4. Malfunctions Due to a Cybersecurity Vulnerability

IoT devices are among the consumer products that most commonly have sensors. Households are rapidly getting accustomed to using IoT gadgets, but one of the still-present problems to overcome is the fact that IoT devices are usually severely lacking in security measures.

Multiple reports from cybersecurity authorities indicate that attacks on IoT devices will go up in 2019. A publication from Avast predicts an evolution in IoT malware that makes it more sophisticated than ever, similar to how both computer and smartphone-based malware got more advanced over the years.

Additionally, a study from Nokia found that IoT botnets accounted for 78 percent of malware carrier network activity in 2018. Researchers are also concerned about hackers breaking into smart city sensors and wreaking havoc for entire communities rather than focusing on consumer devices. In one investigation of three leading companies that provide smart city sensors, there were 17 cybersecurity flaws uncovered, including eight critical ones.

The finding suggests that even if sensor companies and owners have not had known cybersecurity issues yet, the risk is growing and requires thorough management over the years to come. Engineers who create IoT devices can help reduce future infiltrations by making cybersecurity a front-of-mind matter throughout the design and production processes for sensors and other components.


5. Car Oxygen Sensor Problems Due to Low Fuel Quality or Poor Maintenance

Today's automobiles feature an array of sensors, especially if those vehicles have autonomous components such as lane-sensing or obstacle-avoidance capabilities. Sensors also tell people when to alter the tire pressure because it's too low or high for safe driving. However, there's another part that may not be as familiar to some. It's the oxygen sensor, which monitors the level of oxygen in the exhaust. The sensor uses a voltage signal to communicate the results to the car's computer. Then, if needed, the vehicle's computer adjusts the fuel/oxygen mixture delivered to the engine.

When the fuel-to-oxygen ratio is too lean or rich, it can cause the car to run roughly or get poor gas mileage. The sensor may get caked with combustion byproducts such as fuel additives and oil ash over time as well. Skipping regular maintenance, especially for spark plug and air filter changes, can be problematic. These parts promote complete fuel combustion, and incomplete fuel combustion causes buildup in the emissions system.

The oxygen sensor may also have a shorter-than-average lifespan if a person uses a type of gas not recommended for the car or typically chooses low-quality fuel. Car manufacturers can help owners avoid problems by providing oxygen sensor information in the vehicle's manual based on guidance received by engineers. For example, recommendations suggest replacing the oxygen sensor every 60,000-90,000 miles on a car that's less than 15 years old.


Proactiveness Reduces Sensor Problems

This list highlights the array of sensor issues that can result either during production or afterward. When respective parties think ahead about how to steer clear of complications, they should find that their sensors typically offer hassle-free functionality.


About the author

Kayla Matthews is a technology journalist and writer with a focus on the IoT and IIoT, automation, and smart technologies. She writes regularly for Productivity Bytes.