LVL-A7

Pepperl+Fuchs LVL-A7 Vibration Limit Switch.

Technical specifications

• Measuring method: The tuning fork is brought to its resonance frequency by means of a piezoelectric drive. If the tuning fork is covered by liquid, this frequency changes. The electronics monitor the resonance frequency and indicate whether the tuning fork is freely vibrating or is covered by liquid.
• Construction type: compact device; device with short tube
• Operating mode: MAX = maximum safety:; The device keeps the electronic switch closed as long as the liquid level is below the fork.; example application: overspill protection; MIN = minimum safety:; The device keeps the electronic switch closed as long as the fork is immersed in liquid.; example application: dry running protection of pumps; The electronic switch opens if the limit is reached, if a fault occurs or in the event of a power fails (quiescent current principle)
• Rated voltage: - DC-PNP: 10 ... 35 V DC, 3-wire; - AC/DC: 20 ... 253 V AC/DC, 2-wire
• Current consumption: - DC-PNP: < 15 mA; - AC/DC: < 3.8 mA
• Power consumption: - DC-PNP: < 975 mW; - AC/DC: < 850 mW
• Measured variable: density
• Measuring range: min. 0.7 g/cm3, optional> 0.5 g/cm3
• Output type: switching output
• Switching current: max. 250 mA
• Measured value resolution: < 0.5 mm
• Measuring frequency: approx. 1100 Hz in air
• Switching point: 13 mm ± 1 mm
• Non-repeatability: ± 1 mm acc. to DIN 61298-2
• Hysteresis: max. 3 mm
• Switching time: - 0.5 s when tuning fork is covered; - 1.0 s when tuning fork is uncovered; - other switching times on request
• Ambient temperature: -40 ... 70 °C (-40 ... 158 °F)
• Process temperature: -40 ... +100 °C (-40 ... +212 °F); -40 ... +150 °C (-40 ... +302 °F)
• Process pressure (static pressure): -1 ... +40 bar (-14.5 ... +580 psi)
• State of aggregation: liquid
• Density: min. 0.7 g/cm3, optional> 0.5 g/cm3
• Viscosity: 1 ... 10000 mPa/s, dynamic viscosity
• Connection: - cable 5 m; - valve plug NPT1/2; - valve plug QUICKON; - valve plug M16; - plug M12
• Material: see technical information (TI)
• Process connection: - thread ISO 228 G1/2, G3/4, G1; - thread EN 10226 R1/2, R3/4, R1; - thread ASME MNPT1/2, MNPT3/4, MNPT1