How it works
Solid level switches detect when a certain predefined level is reached by the bulk solids inside a silo, tank, or vessel. These sensors are used when it’s not necessary to know where level is at every moment, like with continuous level measurement. A switch output can start or stop conveyors, sound an alarm, or simply turn on a light. Point level switches outputting a binary signal can be integrated into a process control system.
VEGA uses four different technologies for solid level switching: vibration, capacitance, microwave barrier, and radiometric.
Vibration switches, the VEGAVIB and VEGAWAVE series, are contact instruments that monitor vibration amplitude. These switches constantly vibrate at a specific amplitude. The amplitude changes once the solid reaches the vibration switch, and this change activates the output.
Capacitance switches, the VEGACAP series, are also contact instruments, but these measure capacitance in a system composed of the sensor, vessel, and the product inside. Once the solid reaches the sensor probe, there is a change in capacitance, 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 ignore product falling into a vessel.
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 the paper industry, mining, and building materials.
- Minimum or maximum detection with low maintenance costs
- Vibration switches are simple plug and play instruments
- Microwave barrier switches offer simple adjustment
- Radiometric switching is completely non-contact