Fisher 249 caged level sensors provide more stable operation than do cageless sensors for vessels with internal obstructions or considerable internal turbulence.These sensors are designed to measure changes in liquid level, liquid interface level, or density/specific gravity inside a process vessel using Archimedes’ Principle.FeaturesCaged 249 series sensors come standard with a liquid damping orifice in the lower equalizing connection that helps stability where vessel capacitance is small and permits narrower proportional valve settings.Displacer reaction to small specific gravity changes allows these instruments to be used for density applications and in other applications where a response to low levels of input signal change is required.Few moving parts are used. A knife-edged driver bearing in the sensor helps to provide low-friction operation. Sensors are available in ratings up to CL2500.Caged sensors are available in a variety of orientations and connection styles, and all sensors can be either right or left hand mounted.The torque tube can be replaced without removing the torque tube arm.
