Innovative Solutions in Naugatuck, Connecticut, USA, has recently secured FM approval for its TR420E series of float actuated level transmitters.
The TR420E is a top mounted, 316 stainless steel level sensor containing a chain of equally spaced reed switches and resistors. When activated by the vertically moving magnetic float, the variable resistive signal is converted to a proportional voltage or (4-20 mA) current output through the 12 or 24VDC powered conditioning board located in the top mounted, Nema 7 J-box. Available in lengths up to 18 feet, the TR420E features a standard ½ inch repeating increments with optional ¼ inch resolution and can be supplied in a variety of mount sizes and enclosure styles. The various output options are compatible with most programmable controllers and digital receivers.
It carries an FM explosion-proof rating for Class I, Division 1, Groups A,B,C and D; and dust-ignition proof for Class II/III, Division 1, Groups E,F and G hazardous, (classified) locations, indoor/outdoor (Type 4, 4X).
Unlike many solid state level transmitters, the TR420E float transmitter is unaffected by the conductivity or dielectric properties of the liquid. “If it floats. . . .it works!” The staggered reed switch and parallel resistor arrangement also ensure a continuous and accurate signal. Even if one reed switch were to fail, the resulting signal would be affected only at that point. The integral circuit board design, robust stainless steel tube and high pressure float resist high levels of shock and vibration make the TR420E ideal for off-road vehicle fuel tanks, generator set fuel tanks and other combustible liquid storage.
The availability of separate point-level switches for high and low alarms above or below the transmitter range lends added functional convenience in a compact package.
One application employs a TR420E with a specially weighted float to “ride” on the interface between oil and water in an oil-water separator. By adjusting the density/specific gravity of the float, Innovative’s engineers can provide a float that “sinks” through the lower density liquid, like oil, but remains buoyant in the higher density water thereby monitoring the interface of the two dissimilar fluids. The weighted float principle remains one of the most direct, reliable and economical means of sensing fluid interfaces like chemical emulsions, slurries and other dissimilar liquids.