Level sensors are widely used for determining powder or liquid levels. They are also used to find out interfaces between liquids. Two basic types of level-measurements are available – multi-point or point and continuous.
The multi-point or point level sensors mark a particular level and are mostly used as a switch or a high level alarm. On the other hand, continuous level sensors are used for measuring dry or liquid material levels within a specific range. They also offer outputs that constantly indicate the level.
Both continuous and point level sensors can be incorporated into a single device to provide a stepped version of constant level or add a low alarm. Output options include analogue current signals, modulated frequency or frequency, analogue current signal, visual or alarm indicator.
Level sensor technology
Different types of level sensors are manufactured. Options include radio frequency (RF) admittance or capacitive, air bubbler, resistance or electrical conductivity, magnetic or mechanical floats, differential pressure and resistance or electrical conductivity. These sensors can also use microwave or radar, ultrasonic or sonic meters, pressure membrane and radio frequencies.
Sensors that use tuning forks make use of different technologies to vibrate a probe. They continuously monitor the absence or presence of that vibration. Level sensors are basically designed for applications that need a controller, a locally-programmable unit or a simple gauge.