Level monitor with resonance
The type NVI level monitors especially designed for use in powdery to fine-grained and granular bulk solids work on the vibrating fork principle and are practically free of maintenance and abrasion. The devices are particularly durable due to the lack of moving parts. The formation of deposits is mostly impossible because of its single rod shape. The rod is self-cleaning in principle as the vibrations shake off the medium from the rod.
A mechanical system is brought into resonance by an electronic circuit. When a medium covers the probe, this vibration is muffled. This change in the resonant frequency is converted into a switching signal by an electronic system.
The evaluation electronics are well protected within the robust aluminium connection housing with protection class IP 67. It registers the change in vibration and displays this on an LED display. An additional relay output is used to transmit signals. Depending on the material density, settings for the operation mode to use as a security switch or for a switching delay can be applied using three DIP switches.
The robust level monitor with process connection and probe made of stainless steel stand out due to their compact structure, high mechanical resilience and long-term operational reliability. NVIs are also suitable for solids with low bulk density from 0.05 kg/dm3 in the plastics, chemical, food, paper, recycling, building and construction industries and power stations. NVIs are suitable as maximum/ minimum level monitors or as level switches for bulk solids in containers, silos and funnels. Installation is possible from top and from the side so that the devices are not only used as protection against overfilling but can also be easily used for signalling the minimum level.