How it works
Liquid level switches detect when a certain predefined level is reached by the liquid inside a tank or vessel. These sensors are used when it’s not necessary to measure every possible level, like with continuous level measurement. A switch output can start and stop pumps, sound an alarm, or simply turn on a light. Point level switches can be integrated into a process control system.
VEGA uses four different technologies for liquid level switching: vibration, capacitance, microwave barrier, and radiometric.
Vibration switches, part of the VEGASWING series, are contact instruments that monitor frequency. These switches constantly vibrate at a specific frequency. The frequency changes once the liquid or fluid reaches the vibration switch, and this change activates the output.
Capacitance switches, the VEGACAP series, are also contact instruments, but these measure capacitance, or the liquid or fluid’s ability to hold an electrical charge. Once the liquid reaches the switch, the capacitance changes, and the switch output changes state.
Microwave barrier switches use two parts: a transmitter and a receiver. In between is an “invisible” barrier, and the switch is activated once that microwave barrier is broken or interrupted. These switches, called the VEGAMIP at VEGA, can provide “full” or “empty” options, and they can be used to determine when a liquid or fluid is pouring into a vessel. These can also be used as non-contact instruments by shooting through non-conductive vessels.
Lastly, radiometric switches operate similarly in principle to microwave barrier switches, but these instruments use gamma radiation emitted from a source holder while a detector measures the amount of radiation reaching it. Unlike any of the previously mentioned switches, radiometric switches can be installed completely externally, which is why they’re typically used to measure harsh or volatile processes like those seen in oil refining, the chemical industry, and mining.
- Point level detection with low maintenance costs
- Vibration switches are simple plug and play instruments
- Capacitance switches work well with continual buildup
- Microwave barrier switches offer simple adjustment
- Radiometric switching is completely non-contact