Simple installation of capacitive filling level detection sensors

As is generally known, capacitive sensors can detect any electrically conductive medium, provided that its dielectric constant is high enough. As this is true for most liquids and solids and because detection is in many cases possible even through the walls of non-metallic containers, this measuring method is perfect for e.g. contactless filling level detection.


In principle, almost any flush-mountable capacitive sensor can be used. However, the range of products offered by ipf electronic includes various solutions whose specific designs, housing materials, durabi-
lity against environmental influences, etc. make them ideal for use in filling level detection applications. One good example is the capacitive sensor KBQC0100. A particularly noteworthy feature of this sensor is its flat design. At just 8mm high, the device can be installed even in confined areas. The housing has through holes with a diameter of 3.2mm for screw mounting as well as vertical and horizontal recesses for mounting with cable straps or strap retainers.


In the plastic housing (PA) with degree of protection IP68, there are two LEDs for signaling the presence of the voltage supply and for indicating the switching states of the PNP normally-open output. The teach-in line (permanently connected, 2m long PVC cable) is used for calibrating the sensor to an empty or full container. The operating range available for this is between 0 and 10mm in front of the active surface.


A sensor feature that can sometimes be very useful in practice is the test function. If the test mode is active, the output switches on and off irrespective of the current filling level of the container. This allows the downstream evaluation components to be checked extremely simply and conveniently without having to change the filling level in the container and having to modify the wiring of the control unit.