Fluid Level Sensors – More Than Just an On/Off Signal

Fluid Level Sensors – More Than Just an On/Off Signal

In the past, fluid level sensors provided a simple on/off signal, but now sensors are being called upon to supply a great deal more information. The trend towards increased control circuits begin employed in both residential and in industrial device application monitoring is driving the need for more complex and “smarter” liquid level sensors that are capable of more than just an open or closed signal line. In some instances additional information can be signaled with simple magnetic reed switches by adding many reed switches to a PCB to give multiple liquid level point measurements. In this application resistors can be placed in circuit to provide discreet voltage outputs that will indicate one of many possible level points along the travel path of a magnetic float. If a digital signal or custom voltage signals are required by the customer this is accomplished through the use of either onboard or remote signal electronics. The environment in which the sensor will be employed can also determine whether a simpler mechanical float level sensor will work or if a more sophisticated conductivity sensor is more appropriate. A mechanical float switch can suffer failure due to contaminants restricting the movement of the magnet containing float, whereas a conductivity sensor must be able to discern between being submerged in fluid or just having a viscous fluid clinging to the probes of the sensor and of course a standard conductivity sensor that is always submerged in a fluid is highly susceptible to electrolysis.