Capacitive Proximity Sensors can be used to detect non-metal objects, such as liquids and plastics.
There are 6 products of Capacitive.
            
            
               Long-distance type
            
            
                E2K-C
            
        
    Long-distance Capacitive Sensor with Adjustable Sensitivity
            
            
               Cylindrical Proximity Sensor
            
            
                E2K-X
            
        
    General-purpose Threaded Capacitive Sensor
            
            
               Flat Proximity Sensor
            
            
                E2K-F
            
        
    Flat Capacitive Sensor with a Thickness of Only 10 mm
            
            
               Liquid Level Sensor
            
            
                E2K-L
            
        
    Liquid Level Sensor That Is Unaffected by the Color of the Pipe or Liquid
            
            
               Chemical-resistant Proximity Sensor
            
            
                E2KQ-X
            
        
    Fluororesin-coated Capacitive Sensor with Sensitivity Adjuster
            
            
               Long Sensing-distance Capacitive Separate Amplifier Proximity Sensor
            
            
                E2J
            
        
    Flat Capacitive Sensor with Separate Amplifier Ideal for Mounting on Robot Hands.