WEKA continuous tank level gauges are the ideal complement to the Weka bypass system wherever external mounting is not feasible. Fully electronic and with no moving parts other than the float, they deliver reliable tank level values for remote gauging. The XM types work on the voltage divider principle, delivering output voltages between zero and supply voltage in direct relation to the float position. Most types also come in an XT version, in which an integrated converter converts the voltage signal to a 4–20 mA signal (current sink).
How it works
The tank level sensors are installed vertically in the tank to be gauged, and connected by a cable to a remote receiver. Running inside the entire length of the hermetically sealed, pressure-resistant guide tube is a board fitted with reed switches and resistors. Magnets integrated into the float activate the reed switches, which trigger a signal change over the resistors in direct relation to the fill level inside the tank.
The voltage divider principle
The electronic components are installed such that they switch in a controlled 2-3-2 sequence when exposed to a defined magnetic field. This yields an essentially linear output signal with high repeat accuracy and has the advantage that, if one reed switch should fail, the rest of the system will continue to function normally and only that one measuring point will produce a measurement error.
The proven, robust float technology allows sensing of the true liquid level without relying on extrapolated values of indirect measurements such as pressure or echo, and is independent of temperature and air pressure fluctuations. This guarantees a reliable, direct measurement even in tanks with curved walls or other shapes without clear vertical access.
Float technology is the only measuring principle capable of measuring interface levels between two liquids in virtually any size or shape of tank. Wherever two immiscible media with a density difference greater than 0.1 g/ccm need to be gauged, WEKA TLIs deliver the exact level of the media interface.