Monitor aboveground storage tanks that require flex probe solutions

Mag-FLEX is an ideal solution for fuel distribution depots, marine terminals, aviation fueling installations and many other facilities where fuels are stored in bulk. It utilizes the proven Veeder-Root magnetostrictive probe technology installed in over 500, 000 tanks globally. This solution, paired with any Veeder-Root automatic tank gauge (ATG), creates a powerful, affordable inventory management system backed by the support network and reliability of Veeder-Root. It delivers accurate reconciliation of your most expensive on-site assets while eliminating the safety hazard of scaling formidable heights to determine inventory levels of aboveground storage tanks (ASTs). 

Key Features & Benefits

  • Single point of monitoring: Automate product level, water level and temperature monitoring of storage tanks with a Veeder-Root fuel monitoring system.
  • Water detection: Identify possible water intrusion and ensure fuel quality with a water float system. The standard water float included detects water at the 5.5” (14cm) level. An optional low-level water float is also available for water detection at the 1.9” (4.8cm) level, which requires 4” (10.2cm) tank opening.
  • Wireless & Wired applications: Save installation time and cost with wireless technology, which eliminates wiring from the tank to the ATG. Where wireless is not practical, Mag-FLEX accommodates traditional wired installation as well.
  • Scalable solution to various site profiles: The Veeder-Root ATG portfolio offers a wide range of consoles to best suit various site configurations.
  • Flexible, corrugated probe design: Provides for easy transportation and installation.
  • Stainless steel probe shaft: Provides increased protection of the mag wire and probe durability.

Product Form

Part Number Description Console Type Certification
889591-4XX Mag-FLEX Probe with gasoline & water floats, wired TLS-450PLUS, TLS4 and TLS4B UL/cUL
889591-5XX Mag-FLEX Stainless Steel Probe with diesel & water floats, wired TLS-450PLUS, TLS4 and TLS4B UL/cUL
889591-6XX Mag-FLEX Stainless Steel Probe with no water float, wired TLS-450PLUS, TLS4 and TLS4B UL/cUL
889591-1XX Mag-FLEX Stainless Steel Probe with gasoline & water floats, wireless TLS-450PLUS, TLS4 and TLS4B,TLS-350,TLS-300  UL/cUL
889591-2XX Mag-FLEX Stainless Steel Probe with with diesel & water floats, wireless TLS-450PLUS,TLS4 and TLS4B,TLS-350,TLS-300 UL/cUL
889591-3XX Mag-FLEX Stainless Steel Probe with no water float, wireless TLS-450 PLUS, TLS4 and TLS4B,TLS-350,TLS-300 UL/cUL

Flexible and Easy Installation

The flexible design of the Mag-FLEX probe allows it to be coiled, ensuring it can be packed compactly for low cost shipping and conveniently transported to the tank top, quickly ready for an easy installation.

After the Mag-FLEX probe has been installed, the corrugated steel shaft is oriented vertically and held in its operating position by the integral weight and magnet. The probe floats will precisely follow the level changes in the tank and report the presence of any water. The Mag-FLEX probe utilizes magnetostrictive measuring technology to provide consistently accurate and repeatable data.


Product Measurement

Height accuracy

±0.08" (±0.2cm)


±0.02″ (±0.05cm)

Minimum product level reading

7.3″ (18.5cm)

Float size

1.7″ (4.3cm)


Water Measurement




Height accuracy

±0.12″ (±0.3cm)

±0.12″ (0.3cm)


±0.02″ (±0.05cm)

±0.02″ (±0.05cm)

Minimum water level reading

5.5" (14cm)

1.9" (4.8cm)

Float size

1.7" (4.3cm)

4" (10.2cm)


Temperature Measurement

Operating range

-40°F to 140°F (-40°C to 60°C)


±0.36°F (±0.2°C) @ -40°F (-40°C) to 185°F (85°C)
±0.18°F (±0.1°C) @ -4°F (-20°C) to 131°F (55°C)


±0.5°F (±0.5°C)


0.1°F (0.1°C)


 5 Thermistors


Installation Details

Probe shaft length

Up to 72’ (22m) tank height

Tank adapter/tank entry

R 1.5" (3.8cm) screw-in unit

Height adjustment range

±9.8" (24.9cm)

Electrical connection

M12 plug-in connection

Protection class



Sensor Materials

Probe canister

Stainless steel 303

Rigid shaft sections

Stainless steel 304

Corrugated flexible shaft and floats

Stainless steel 316 Ti


Stainless steel 303

Magnet casing

Conductive plastic


General Information


Tank adapter made of stainless steel. Weight made of stainless steel.




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