The level monitor model NSV has decisive advantages, especially with bulk goods with low bulk densitiy. Vibrations are induced in a stainless steel fork by a piezoelectric crystal. If the medium comes into contact with the vibrating fork, this vibration is damped.This damping is detected in a pluggable evaluation module and transformed into a potential-free limit contact. In addition to the standard version NSV-8200, the devices can also be provided for vertical installation with an extended neck pipe (NSV-8201). The maximum length of the neck pipe is 3000 mm. The plug-in evaluation module can be changed easily so that the devices are really easy to maintain. Operation can be set for maximum or minimum security by means of a selector switch (A and B). The respective switching status of the relay is indicated by a LED.