LVP-51-R Non-Intrusive RF Capacitance Sensors Selectable NO or NC

Supported Applications

The Omega LVP-51 series consists of non-intrusive RF capacitance level switches designed for liquid detection through plastic or fiberglass tank walls. These sensors generate a high radio frequency signal from an electrode on the exterior to detect changes in dielectric value, determining liquid presence without penetrating the vessel wall. The series is intended for liquids with a dielectric constant between 20 and 80 (with some sources noting capability down to 10 units) and conductivity greater than 100 μS/cm.

Documented applications include:

• Liquid level detection in non-metallic tanks
• Ultrapure and sanitary applications using weld-on fittings for polyethylene, fiberglass, or polypropylene vessels

Operating Conditions & Performance

The LVP-51 series operates within a temperature range of -40° to 80°C (-40° to 176°F). The sensor is rated for tank wall thicknesses up to 25.4 mm (1") and requires non-metallic mounting surfaces; installation on metallic tanks or within 6" of any metallic object is prohibited.

Performance specifications include:

• Accuracy: ±1 mm (0.04") in water
• Repeatability: ±0.5 mm (0.02") in water
• Dielectric Range: 10 to 80 dielectric units @ 1 MHz (or > 20 constants per manual)
• Power Supply: 12-36 VDC with maximum consumption of 25 mA

The enclosure is constructed from Polysulfone and carries a NEMA 4X (IP65) or NEMA 4 (IP65) rating, described as splash-proof and chemical resistant. The sensor is not designed for immersion.

Configuration Options

The series offers configurable mounting options and output signals to accommodate specific installation requirements:

• Mounting Brackets/Fittings: Available in Polyethylene (PE) as model LVP-91 or Polypropylene (PP) as model LVP-92. Fittings utilize 3M adhesive for temporary holding during welding, glazing, or strapping.
• Cable Options: Standard length is 3 m (10') with a shielded 4-conductor #22 AWG cable. Extended lengths are available: add suffix '-25' for 7.62 m (25') or '-50' for 15.24 m (50'). Maximum supported length is noted as 305 m (1000').
• Output Signals:
    • Selectable NO/NC SPST mechanical relay output (60 VA, 1A maximum; CE rated at 60 Vac/Vdc @ 1 A)
    • FET switch and 4-20 mA sensor outputs
    • Single LED for calibration and liquid status feedback
• Electrical Connection: Single, 1/2" NPT conduit entrance.

Key Product Differences

The primary model LVP-51-R is the non-intrusive capacitance sensor with a Polysulfone housing. Distinctions in the series are defined by mounting hardware and cable configuration:

• LVP-91 vs. LVP-92 Fittings: The LVP-91 fitting is made of PE, while the LVP-92 fitting is PP; both measure 6.4 x 6.4 cm (2.5" x 2.5").
• Cable Length Variants: Standard units include a 3 m cable; variants with suffixes '-25' or '-50' provide extended lengths for additional cost.