The KENCO Magna-Site™ is a magnetic liquid level indicator used to determine the volume of liquid contained within a vessel. Because the Magna-Site™ eliminates the need for glass, high pressure applications and hazardous locations are protected from the danger of a chemical spill due to potential glass failure.
The KENCO Magna-Site™ utilizes three major components: the gauge housing chamber, the magnetic float and the magnetic flag assembly. The gauge housing chamber is mounted adjacent to the side of the vessel. It is constructed to withstand the same temperatures and pressures as the tank itself. It is equipped with the appropriate tank mounting connections for easy installation and to allow equalization of liquid level in tank and gauge.
Inside the gauge housing chamber is the magnetic float, which contains radially-positioned magnets to provide a 360° magnetic-flux field. Each float is internally weighted based on specific gravity so that the liquid level in the gauge coincides with the location of the magnets inside the float. Attached to the gauge housing chamber is the magnetic flag assembly. This is the visual means of liquid level indication for the KENCO Magna-Site™. The assembly is made up a of a series of bi-colored fluorescent flags. As the magnetic float rises and falls with the liquid level in the gauge housing chamber, a magnet embedded in each flag reacts to the 360° magnetic flux of the float. This magnetic interaction causes each flag to rotate 180°. The flags below the magnetic flux of the float will flip to fluorescent green, while those flags above the float level remain steel gray.
KENCO loop powered transmitters electronically monitor the location of the magnetic float within the Magna-Site gauge housing, providing an output in a unit of measure, as a percent of span or a 4-20mA output. The transmitter is available up to a length of 300 inches. Zero and span may be adjusted by using the HART® communications protocol or it may be manually calibrated using the keypad display inside of the explosion proof housing. These transmitters operate within a process temperature range of -40°F to 300°F (-40°C to 148.8°C ). Field replaceable electronics are potted and encapsulated. KENCO transmitters are available as standard with NEMA 4X/7 explosion-proof housings. These housings feature an industrial epoxy coating for corrosion resistance. All KENCO level transmitters use non-contacting, magnetostrictive technology. This simple design ensures no scheduled maintenance or re-calibration — ever. Accurate, non-contact float location sensing is achieved with absolutely no wear to any of the sensing elements.
The level transmitter is composed of two concentric members. The outermost member is a protective stainless steel chamber that withstands aggressive or harsh process industry environments. The heart of the transmitter design is the innermost member, the waveguide, a formed element constructed of a proprietary magnetostrictive material.
A pulse is induced in the waveguide by the momentary interaction of two magnetic fields, one from an electric current pulse launched along the waveguide and the other from the magnet inside the float. This interaction produces a strain pulse that travels along the waveguide. The location of the magnet inside the float is determined by measuring the elapsed time between the launching of the electronic pulse and the detection of the strain pulse by the sensor head. The time period measurement is used to produce a 4-20mA output.