Capacitive Sensors for Safe Detection of Aggressive Media
In quite a number of fill level applications there are liquids to be detected which require sensor housings and media containers to be made of materials of strongly improved properties due to their chemical reactivity.
Since the sensors' electrical field of detection is capable of penetrating through insulating materials such as plastics, glass, cardboard etc., non-invasive detection of both liquids and solid matter is possible from the outside.
Capacitive sensors can therefore monitor fill levels in closed containers whilst being attached to the outside container wall. Compared to sensing methods requiring direct contact with matter, there are a number of advantages.
On one hand, this approach provides an excellent protection for the sensor itself, which assures a long live expectancy as well as a high degree of process safety. On the other hand, the medium to be detected or monitored cannot be contaminated by the sensor’s housing.
The detection behaviour of capacitive sensors is influenced by the dielectric constant of the surrounding materials. Certain limitations apply when detecting liquids and objects exhibiting a low dielectric constant using the existing, flush-mounted capacitive sensors.
Baumer has recently launched a family of capacitive sensors with increased sensing distance. The products provide new possibilities to reliably tackle various fill level applications. Faster installation and an increased process reliability are the user benefits in practical applications.
Consequently, "detecting defying media safely" is facilitated considerably with the new capacitive sensors from Baumer.
How to select the correct sensor in only 60 seconds:
The sensor selector matrix (see right) has been designed to assist in selecting the best suited sensor based on the material/medium to be detected and the material the container is made of.
First step: select the medium to be detected in one of the horizontal lines. Second step: chose the container material through which the selected medium must be detected non-invasively. At the intersection of the line and the column you will find the capacitive sensor best suited for your application.
- Reliable detection through insulating container materials
- Extended sensor life span and high process reliability
- Reliable detection, even of materials with low dielectric constants
- Reduced installation time