Level switch with no moving parts

Device detects liquids and dry substances with short response time.

08/13/2010


Baumer LBFS level switch seriesBaumer has released its new LBFS level switch series, which the company says is a cost-effective and reliable alternative to vibration level switches. The device is able to detect viscous or dry substances as well as liquids, and can be mounted in any position in tanks or pipelines. The sensor is unaffected by flow, turbulence, bubbles, foam, and suspended solids. With a small and smooth sensor head, even adhesive media do not stick to it.

Baumer suggests many appropriate applications and industries, including high and low levels in tanks and pipelines, overfill protection, dry running protection of pumps, and phase separation in oil-water mixtures. Its corrosion-resistant housing can be installed through a pipe or vessel wall using a threaded hole and appropriate sealant. Response time is 0.2 seconds so it can be used in fast filling processes. The operating temperature range is -40 to 115 °C.

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The LBFS transmitter sweeps a frequency range which becomes subject to a phase shift depending on the medium. When in contact with the medium, which has a dielectric constant outside a selected range, an electronic switch is triggered. The high sensitivity over a sensing range of dielectric constants from 1.5 to >100 allows detection of all kinds of powders, granulates, and liquids. Baumer says that even difficult substances like polyamide granules or paper can be detected reliably. This compares favorably to other measuring methods like vibrating forks, conductive ultrasonic, or optical sensors. The LBFS series has no moving parts and is not sensitive to changes based on conductivity, temperature, or pressure.

Edited by Peter Welander, pwelander(at)cfemedia.com
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