National Magnetic Sensors, Inc - Multi Level Float Sensors, Single Level Float Sensors, AST Sensors, Bottle Switches, etc.


Continuous Transmitters

Continuous Liquid Level Indicator is achieved by using hermetically sealed magnetic reeds and fixed precision resistors arranged in a linear network. A continually variable resistance in incremental steps, is generated by using a magnetic float as a "wiper". The sensor operates much like a typical potentiometer. An excitation voltage is applied to the sensor and the variable signal, which represents liquid level, is used to drive a meter or transmitter.

Repetitive Accuracy to within of liquid level is constant throughout the length of the unit which is directly proportional to the depth of the tank. At any position the float may occupy, a sequential reed closing/opening pattern varies the resistance in the circuit. Because of the positioning of the reeds, a positive signal change occurs with every of liquid level movement.

Direct Contact Measurement eliminates the need for time consuming calibrations or adjustments which plague more complicated measurement devices. The simple operation of the potentiometer-type circuit operated by a positive acting float provides trouble free operation apart from completing calculations or interpretation circuitry. The float is in CONTACT with the liquid and level change is DIRECTLY read as a changing voltage.

STANDARD MODELS (Up to 10' in Length) All Stainless
All Polypropylene
Stainless & Buna-N (shown above)
Stainless & Polyproylene (shown above)
CUSTOM MODELS National has constructed special sensors up to 18' in length with 8" diameter floats for various applications. Inquire for details