Vibration Limit Switch Provides Maintenance-Free Level Sensing of Bulk Solids

July 11, 2007
Pepperl+Fuchs introduces Vibracon LVL-B Series Vibration Limit Switches.  Vibracon LVL-B Series sensors are insensitive to material build-up, external vibration and flow noise, and have no mechanical moving parts for reliable, maintenance-free level sensing of bulk solids materials.  Specifically designed to satisfy the unique level sensing needs of the bulk solids industry, the Vibracon LVL-B Series is an ideal solution for sensing fine or coarse-grained material such as grain, sugar, animal feed, beans, gypsum, sand, plastic granules, chalk, cereals, rice, detergents and cement, among others.  They are FM and CSA certified as Dust Ignition Proof (DIP) for Class II and Class III, Divisions 1 and 2, Groups E-G, making them a suitable solution in hazardous area applications.Vibracon LVL-B Series sensors feature a compact 250 mm (10 in.) vibrating rod, and are available with 500 mm (20 in.), 1000 mm (40 in.) and 1500 mm (60 in.) extension pipes, making them suitable for installation and operation in literally any direction to suit any bulk solids application requirement.  The sensor itself is constructed of stainless steel to eliminate abrasion issues.  A plastic housing with cover sight glass makes the switch status easily visible from outside the hopper.  An aluminum housing is also available.  The principle of operation is simple.  The probe vibrates at a fixed frequency and when the material damps the vibration, the LVL-B will switch its output to alert the control system.   • Ambient temperature - -40 ... 70 °C (233 ... 343 K) • Storage temperature - -40 ... 85 °C (233 ... 358 K) • Process temperature - -40 ... 150 °C (233 ... 423 K) • Medium pressure limits - -1 ... 25 bar • State of aggregation - solids • Solid contents - ? Ø25 mm • Bulk density - ? 200 g/l, not fluidized • Protection degree - IP66/IP67, Nema 4x • Electromagnetic compatibility - NE 21 • Protection degree - EN60529 • Climate class - EN 60068, part 2-38, fig. 2a