Tue. Jun 18th, 2024

Magnetic Level Model BNA By WIKA

Bypass level indicator, model BNA with option level sensor and magnetic switch

The WIKA model BNA bypass level indicator consists of a bypass chamber, which, as a communicating interface, is connected laterally to a vessel via 2 process connections (flanged, threaded or welded). Through this type of arrangement, the level in the bypass chamber corresponds to the level in the vessel. The cylindrical float (with a permanent magnet system, mounted within the bypass chamber) transmits the liquid level, contact free, to the outside via the magnetic roller display mounted on the bypass chamber. In this are fitted, at 10 mm intervals, red/white plastic or ceramic rollers with bar magnets.

Through the directional magnetic field of the permanent magnet system in the cylindrical float, the magnetic rollers, through the wall of the bypass chamber, are turned through 180°. For an increasing level from white to red; for a falling level from red to white.  Thus the bypass level indicator displays the level of a vessel without a power supply – visible as a red column.


■ Simple, robust and solid design, long service life
■ Level displayed proportional to volume or height
■ Individual design and corrosion resistant materials make the products suitable for a broad range of applications
■ Pressure range from vacuum up to 400 bar
■ Temperature range up to 450 °C
■ Density ≥ 340 kg/m³
■ Explosion-protected versions
■ Interface measurement and overall level from Δ density ≥ 100 kg/m³
■ Level displayed proportional to volume or height
■ Bypass chamber and float from stainless steel 1.4571, 1.4404 or special materials


■ Pressure- and gas-tight separation between chamber and display/measuring equipment
■ Measuring and indicating of the level of aggressive, combustible, toxic, hot and contaminated media
■ Functioning of the magnetic display guaranteed even in the case of power failures
■ Continuous measurement of levels, independent of physical and chemical changes of the media such as: Foaming, conductivity, dielectric constant, vapours, bubble formation, boiling effects
■ Special versions: Food compliant , coatings, liquid gas, heating jacket

Illustration of the Principle

Magnetic System

The magnetic system is assembled from a pole disc and various magnets. These can be individually adapted to the different chamber dimensions and for temperatures up to 450 °C.

Special Features

■■ Process- and system-specific production
■■ Operating limits:
– Operating temperature: T = -196 … +450 °C
– Operating pressure: P = vacuum to 400 bar
– Limit density: ρ ≥ 340 kg/m3
■■ Wide variety of different process connections and materials
■■ Mounting of level sensors and magnetic switches possible as an option
■■ Explosion-protected versions

[button link=”http://www.emet-impex.com.pl/wika/bna-k-en.pdf” icon=”Select a Icon” side=”left” target=”blank” color=”e84e0f” textcolor=”ffffff”]Learn More[/button]
For more Information Contact:

WIKA Instrumentation Corporation (Thailand) Co.,Ltd
850/8 Ladkrabang Road, Ladkrabang, Bangkok 10520 Thailand.
Tel: (66) 2326 6876 – 80 Fax: (66) 2326 6874
Email: info@wika.co.th
Website : [ot-link url=”http://www.wika.co.th/”]www.wika.co.th [/ot-link]

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