Made In The U.S.A. Since 1938

Lumenite Control Technology, Inc.

Engineers • Designers • Manufacturers

SHOWN Transmitters :

MLST-4220 Sanitary (left)

MLXT-4220 Industrial (right)

What Is Capacitance?

        "The Capacitance Principal" of level measurement says the output signal in milliamps

is dependent on the formula :


        Capacitance (C) = Dielectric Constant (K) * Area of Parallel

Plates (A) ÷ Distance Between Parallel Plates (D) or C = KA / D.


      In a level measurement application,  the dielectric constant “K” is a value greater than 1.

The value “A” is dependent on the diameter and length the level probe.  The value “D”

is the distance from the probe to the tank wall,  ground reference probe or concentric

tube.  Consequently,  capacitance (C) and the resultant mA output increases as the dielectric

constant increases,  the probe diameter and length increases, and the distance from the

probe to tank wall (ground probe or tube),  decreases.

Continuous Level Transmitters

        MLST and MLXT - 4220 capacitance level transmitters are for sanitary and industrial

level transmitter applications.  They provide a continuous 4-20mA,  20-amA,  1-5VDC or

5-1VDC analog output proportional to the material level in any shaped tank.  They can be

used for conductive, non-conductive liquids and moist granular solids.


        MLST and MLXT - TEMP - 4220’s are combination level / temperature transmitters are

for sanitary and industrial applications.  In addition to having all of the standard

specifications,  they provide 2 separate 4-20mA outputs measuring level and temperature

with one probe and one tank connection.  Temperature ranges from -100˚ to 1,000˚F.

4220 Specifications

• Resolution to better than 1 part in 10,000

• Accuracy and repeatability to less than 0.1% of span

• Microprocessor based transmitter with on board digital to analog conversion assuring negligible output

  current error of 0.003%

• Linearity of better than 0.003% over industrial temperature range of -20˚F to 160˚F

• Designed with most up to date surface mount, integrated circuits and components

• Standard range of 0.0001 picofarads to 15,000 picofarads allowing the 4220 to span 4-20mA

   over 1 inch of water, (high sensitivity) or hundreds of feet of water (low sensitivity)

• Non interacting zero and span

• Cancel Coat™ circuitry and superior resolution eliminate the readout errors cause by

   conductive coatings on the sensing probe

Lumenite® Control Technology, Inc

2331 N 17th Ave.    Franklin Park,  IL 60131 U.S.A.

Phone : 847-455-1450    Fax : 1-847-455-1450

E-Mail :    Main Web Site :