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SWI TR420E Series | Continuous Output Float Level Transmitter For Hazardous Locations

USA Toll Free: 1-800-730-0302 Tel: 416-240-1920 -

Sensors and Switches are mechanical-type sensing devices that do not require power to operate. Engineered based on time-proven principles such as buoyancy, conductivity, magnetic latching, capacitance and more, SWI sensors and switches are manufactured to provide reliable industrial process measurement year after year. Click on a sensing device below to learn more about our available sensors and switches product line.

SWI TR420E Series | Continuous Output Float Level Transmitter For Hazardous Locations


The vertically-mounted TR420E Continuous Output Level Transmitter for Hazardous Locations is equipped with an integral signal conditioner and provides a reliable 4-20 mA, 0-5 VDC or 1-5 VDC proportional electronic output in tank levels up to 15 feet. It can be used to input programmable controllers, meters and other digital receivers for accurate and continuous measurement in many liquid level applications. The TR420E is FM-approved with an explosion-proof rating for Class I, Div I, Groups A, B, C & D and an dust ignition-proof rating for Class II/III, Div I, Groups E, F & G hazardous (classified) locations, indoor/outdoor (Type 4, 4X). Float materials are available in stainless steel with a selection of mounting types. Additional options include high level and low level alarms as well as SPST 100 VA or SPDT 30 VA switch contacts.

Principles of Operation

As the float travels with the fluid level within the tank, the float's internal magnets actuate a series of reed switches and resistors along the stem. The signal is electronically conditioned through the built-in transmitter board to provide a proportional current output.

SWI TR420E Series


  • Two-Part Assembly: Junction Box & Sensing Probe
  • FM-Approved Class I, Div. 1, Groups B, C & D
  • Interchangeable Solid-State Electronics
  • Watertight NEMA 7 & 9 Enclosure
  • Probe Lengths Up to 15 Feet
  • Optional Weighted Float for Oil/Water Interface


  • Food & Beverage Processing
  • Medical
  • Fuel Storage
  • Underground Storage Tanks
  • Pharmaceutical
  • Chillers
  • Cooling Towers
  • HVAC
  • Semiconductor Processing


  • Response Time: < 1/2 Second
  • Linearity: ± 0.50%
  • Power Consumption: 1.3 VA
  • Independent Switch Contacts: 100 VA SPST or 30 VA SPDT


TR420E 316 Stainless Steel  -40º to +300º F (-40º to +148.9º C) 750 PSIG (51.7 bar) 12 VDC or 24 VDC 4-20 mA, 0-5 VDC or 1-5 VDC 1/4" or 1/2"
TR420E6 316 Stainless Steel  -40º to +300º F (-40º to +148.9º C) 750 PSIG (51.7 bar) 12 VDC or 24 VDC 4-20 mA, 0-5 VDC or 1-5 VDC 1/4" or 1/2"


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About Us

Metex Corporation Limited has been providing superior products and services to the process control, chemical treatment, waste water, industrial and manufacturing industries for over 25 years. It is our goal to continually provide our customers with the best possible equipment, technology, and service.


Our Products

Dataloggers, sensors, pumps, recorders, hand held instruments, flow instrumentation, level controls, valves, instrumentation, containers, tanks, transmitters, data loggers, digital indicators, mixers and agitators, pressure intrumentation, analyzers and controllers for a variety of industrial applications such as water quality, pH/ORP and more.

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Water Analyzers and Controllers, Wireless Products, Corrosion Monitoring Equipment, Cooling Tower and Boiler Controllers, a wide variety of Pumps, Valves, Dataloggers and Recorders, HVAC, Instrumentation, Skids and Systems, Containers and Tanks from world leading manufacturers are products you will find on this site.

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