„Fluid level sensors that are reed switch based are low power devices that don’t require complex electronics, making them very appealing for most applications.“
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Introduction
Standex Electronics Fluid Level Sensors
Environmental Trends Affecting Fluid Level Sensing
Conclusion
Additional Resources
Capacitive Level Sensors (CLS)
Hall Effect Level Sensors (HLS)
Introduction
In the past, fluid level sensors provided a simple on/off signal. However, sensors today are being called upon to supply a great deal more information. Both residential and industrial device application monitoring is driving the need for more complex and „smarter“ liquid level sensors. Smart sensors can do more than just an open and close. Simple magnetic reed switches can be designed „smarter“, to signal additional information. For instance, adding many reed switches to a PCB will provide multiple liquid level point measurements. Likewise, placing resistors in the circuit will generate discreet voltage outputs. These voltage outputs are used to indicate one of many possible fluid level points along the travel path of a magnetic float. Hence, turning this reed sensor into a smart sensor.
If a digital or custom voltage signal are required by the customer, this is accomplished using either onboard or remote signal electronics. The sensor environment determines whether a simple mechanical float sensor or a more sophisticated sensor technology (capacitive or hall effect) is appropriate. Environmental contaminants can restrict the movement of a mechanical float level sensor. Likewise, a conductivity sensor is highly susceptible to electrolysis. Additionally, conductive sensors must be able to discern between being submerged in fluid or just having a viscous fluid clinging to the probes.
![Reed Switch shown in fluid level detection and monitoring application](https://standexelectronics.com/wp-content/uploads/2020/11/fluid-level-sensor-level-monitoring-detection.gif)
Reed Switch shown in fluid level detection and monitoring application.
Standex Electronics Fluid Level Sensors
Reed switch-based level sensors are easily customizable and simple to install. Moreover, they are low power devices that don’t require complex electronics. In other words, reed technology sensors are very appealing for most applications.
One application example is a brake fluid sensor used to signal a dangerously low automotive brake fluid level, in the reservoir. A second example is a dishwashing machines overfill condition sensor used to prevent excessive water usage and flooding outside the unit. In this example, reed switch technology replaced a microswitch. Reed switches and a thermistor were mounted on a PCB and packaged with an all-in-one level sensor consisting of two magnetic floats. One float and switch provide overflow protection that shuts down the dishwasher. The other float moves between two reed switches to give multiple level readings.
Since customers now expect more than just an on/off signals from level sensors. Level sensors need to provide smart information to the end user whether it’s warning of dangerous fluid levels or just for convenience. Modern laundry equipment uses bulk detergent level sensors, every time the appliance operates. That way the customer doesn’t have to. Most importantly, ’smart‘ feedback delivers ease of use and convenience, customers appreciate.
Environmental Trends Affecting Fluid Level Sensing
Moreover, environmental initiatives are another big driver of new sensor technology and applications. Energy monitoring for both individual and household appliances and industrial water tanks is one example. Environmental sensors today also must be „smart“ designs with wireless and machine to machine (M2M) interaction, for remote monitoring. That’s where Standex Electronics steps in with innovative, high-quality reliable components that fit the bill for such applications.
Imagine you are on vacation and you get a text message alert that the sump pump has stopped working on the air conditioner drain line! As a result, you can respond to that emergency immediately. Consequently, preventing significant structural damage. First, only „smart“ level sensors with onboard electronics can provide this type of alert. Second, Standex Electronics smart sensor designs can handle these tough sensing requirements.
Furthermore, clean water and water treatment have huge environmental implications for level sensing. In fact, water treatment in developing nations is perhaps the largest market for level sensors. Sensor applications include sewer water, gray water, and clean water. Fluid level sensors monitor critical water usage levels to avoid wastage. Finally, Standex Electronics can meet the specifications for the National Science Foundation (NSF) regulations and stainless sensor requirements for various drinking water and food service applications.
Conclusion
In conclusion, level sensors today provide smarter and more accurate feedback either remotely or at the device level. Standex Electronics products can intelligently provide the functionality necessary to make products smarter, more efficient, and more productive. Most importantly, Standex Electronics smart sensor designs use less energy, improve resource management, lower costs, and increase performance.
Finally, our versatile engineering expertise in magnetic sensing technologies and custom packaging allows us to be a one-stop-shop for your sensing requirements. Contact our engineers today to discuss your specific design requirements.
Additional Resources
Learn more about our fluid sensor capabilities described in our thought leadership interview with Elena Tischer, Product Manager Level Sensors.
Check out these additional resources on Hall Effect and Capacitive Level Sensor solutions.
Hall Effect Level Sensors (HLS) | Capacitive Level Sensors (CLS) |