Magnetostrictive Level Transmitters

Magnetostrictive Level Transmitters

KT Series Magnetostrictive Transmitter

The in-tank liquid level transmitter is a continuous multi-functional Magnetostrictive transmitter that provides product level, interface level, and temperature to the user via Analog (4-20mA) with HART®, Modbus RTU (Remote Terminal Unit) or DDA (Direct Digital Access). Magnetostrictive technology is one of the most accurate and repeatable level technologies available to date. Once the transmitter is installed and calibrated, there is no requirement for scheduled maintenance or recalibration.

Principle of Operation

The principles of magnetostriction are used to create a reliable position measurement system for use in industrial environments. Inside the sensor, a torsional strain pulse is induced in a specially designed magnetostrictive waveguide by the momentary interaction of two magnetic fields. One field comes from a magnet located inside a float, which moves up and down the outside of the transducer tube. The other field is  generated from a current pulse which is applied to the waveguide. The interaction between these two magnetic fields produces a strain pulse which travels at sonic speed along the sensor waveguide until the pulse is detected at the head of the transducer. The position of the moving float magnet is precisely determined by measuring the elapsed time between the application of the current pulse and the arrival of the strain pulse. As a result, a reliable position measurement system is created that is capable of providing an accurate and repeatable measurement.


  • Simultaneous Measurement of Multiple Process Conditions:
    -Product Level
    -Interface Level
  • No Scheduled Maintenance or Recalibration
  • Field Repairable
  • Inherent Accuracy ±0.039” (±1 mm)
  • 200 Point Strap Table
  • API Temperature Corrected Volumes
  • Integral Display
  • Password Protected Data Entry
  • Hazardous Area Certified
  • Intrinsically Safe


  • Hydrocarbons
  • Solvents
  • Water
  • Acids
  • Caustics
  • Condensate
  • Clean Liquids

Industries Served

  • Chemical
  • Petroleum
  • Water/Wastewater
  • Pharmaceutical
  • Pulp & Paper
  • Power
  • Aerospace



Float Selection

KENCO offers a wide variety of floats to meet the most demanding applications. Floats with specific gravities as low as 0.35 are available. Floats are available in the following materials: 316 Stainless Steel, Hastelloy-C® and Teflon®. Due to the wide range of variables possible in process conditions, no single float can be used in all applications. KENCO will assist you in choosing the best float for your application.

KENCO recommends selecting a float with a specific gravity at least 0.05 less than the fluid being measured. In addition, there must be a minimum difference of 0.05 S.G. between fluids for interface applications.

Level Output

  • Measured Variable = Product Level and Interface Level
  • Order Length (measurement range plus inactive zone) =
    – KTR (rigid sensor) : 12″ to 300″ (305mm to 7620mm)
    – KTF (flexible sensor): 62″ to 866″ (1575mm to 21996mm)
    *Contact Factory for Longer Lengths
  • Inherent Accuracy = ±0.039″ (±1mm)
  • Repeatability (any direction) = 0.001% F.S. or 0.015″ (0.381mm); Whichever is Greater

Temperature Output

  • Measured Variable =
    – Analog (4-20mA) with HART: Single Point Temperature
    – Modbus RTU / DDA: Average and Multipoint Temperatures
  • Temperature Accuracy =
    – Analog (4-20mA) with HART:
    ±0.5 °F from -40 °F to 221 °F (±0.28 °C from -40 °C to 105 °C)
    – Modbus RTU / DDA:
    ±0.4 °F from -40 °F to -4 °F (±0.2 °C from -40 °C to -20 °C)
    ±0.2 °F from -4 °F to 158 °F (±0.1 °C from -20 °C to 70 °C)
    ±0.3 °F from 158 °F to 212 °F (±15 °C from 70 °C to 100 °C)
    ±0.9 °F from 212 °F to 221 °F (±0.5 °C from 100 °C to 105°C)


  • Input Voltage = 10.5 to 28 Vdc
  • Fail Safe =
    – Analog (4-20 mA) with HART: Low (3.5 mA default) or High (22.8 mA)
    – Modbus RTU / DDA: High, Full Scale
  • Reverse Polarity Protection = Series Diode
  • EMC (Electromagnetic Compatibility) = EN 61326, EN 61326 -2-3, EN 61326-3-2, EN 61000-6-2, EN 61000-6-3, EN 61000-4-2, EN 61000-4-3, EN 61000-4-4, EN 61000-4-5, EN 61000-4-6, EN 61000-4-8, EN 61000-4-11


  • Enclosure Rating = IP65
  • Humidity = 0-100% Relative Humidity, Non-Condensing
  • Operating Temperatures =
    – Electronics: -40 °F to 160 °F (-40 °C to 71 °C)
    – Sensing Element: -40 °F to 257 °F (-40 °C to 125 °C); Contact Factory for Specific Temperature Ranges
    – Temperature Element: -40 °F to 221 °F (-40 °C to 105 °C)
  • Vessel Pressure =
    – Rigid Metal Sensor Tube: 1000 psig (69 bar)
    – Rigid Teflon Sensor Tube: 25 psig (1.75 bar)
    – Flexible Sensor Hose: 435 psig (30 bar)
  • Materials =
    – Wetted Parts: 316L stainless steel, Hastelloy C (KTR only)  or Teflon® (KTR only); Contact Factory for Other Options
    – Non-Wetted Parts: Epoxy Coated Aluminum or 316 Stainless Steel

Electrical Housing Dimensions

  • Single Cavity (epoxy coated aluminum) = 5.7″ W x 5″ D x 4.3″ H (145mm W x 127mm D x 109mm H)
  • Dual Cavity (epoxy coated aluminum) = 4.6″ W x 5″ D x 8.1″ H (117mm W x 127mm D x 206mm H)
  • Single Cavity (316 stainless steel) = 7″ W x 5.3″ D x 6″ H (178mm W x 135mm D x 152mm H)

Mounting Connections

  • Rigid Sensor = 3/4″ NPT Adjustable Fitting, 3/4″ BSP Adjustable Fitting or Flanged
  • Flexible Sensor = 1″ NPT Adjustable Fitting, 1″ BSP Adjustable Fitting or Flanged


  • Connections = 4-wire Shielded Cable or Twisted Pair, Daniel Woodhead 6-pin Male Connector, 180″ (4570mm) Integral Cable with Pigtail

Electrical Housing Connections

  • Single and Dual Cavity = 3/4″ FNPT Conduit Opening

Electrical Housing LCD Display

  • Measured Variables = Product Level, Interface Level and Temperature