The intrinsically safe reflective ultrasonic level transmitter provides continuous level measurement up to 9.8’ (3m) with a 4-20 mA analog signal output, and is configured via our WebCal software. The non-contact liquid level sensor features our proprietary Reflective Technology™ that delivers reliable level measurement in condensing environments. Select this sensor for small tanks with non-foaming and mildly vaporous media such as chemicals, water, wastewater and oil. Typical applications include day tank, IBC or drum, cooling tower, skid or machine, process tank and waste sumps.


  • Offered in 1.5m (4.9’) and 3m (9.8’) measurement ranges
  • Reflective Technology™ measures reliably with condensation
  • Narrow 2” (5cm) beam width for applications with limited space
  • Configuration is easy with WebCal software and USB adapter
  • Short 1.5” (3.8cm) dead band maximizes tank filling capacity
  • PVDF transducer and PP enclosure for corrosive environments
  • Fail-safe diagnostics with selectable fail-safe signal outputs
  • Type 6P (IP68) compact enclosure for small tank applications
  • Automatic temperature compensation from -40º to 80º C.


Condensation is the most common variable in liquid level applications. Condensation attenuates the acoustic signal of ultrasonic sensors with horizontal transducers, weakening their signal strength and signal to noise ratio by up to 50%, and substantially reducing their measurement reliability. At the core of Reflective Technology™ is a simple fact. Unlike flat horizontal surfaces, significant water droplets cannot adhere to smooth vertical surfaces. By orienting the transducer vertically, condensation runs off the transducer and does not affect sensor performance. The unimpeded transmit and receive signals are redirected to and from the liquid off a 45º reflector, delivering reliable level measurement. Thanks gravity.

Reflective Transducer
Reliable Measurement
Horizontal Transducer
Signal Attenuation


P/N Description From
US01-0001-00 1.5m (4.9′) range, 2″ NPT, w/o Fob $645.00
US01-0001-01 1.5m (4.9′) range, 2″ NPT, w/Fob $710.00
US01-0011-00 1.5m (4.9′) range, 2″ G, w/o Fob $645.00
US01-0011-01 1.5m (4.9′) range, 2″ G, w/Fob $710.00
US03-0001-00 3m (9.8′) range, 2″ NPT, w/o Fob $715.00
US03-0001-01 3m (9.8′) range, 2″ NPT, w/Fob $780.00
US03-0011-00 3m (9.8′) range, 2″ G, w/o Fob $715.00
US03-0011-01 3m (9.8′) range, 2″ G, w/Fob $780.00
LB12-1001 Intrinsic safety barrier $1,200.00


WebCal software is a PC utility program that enables users to easily configure and test compatible Flowline level sensors to their measurement and control requirements. Download your free copy.


Range: US01: 1.5” to 4.9’ (3.8cm to 1.5m), US03: 4” to 9.8’ (10.1cm to 3m)

Accuracy: US01: 0.125” (3mm), US03: ± 0.2% of range

Resolution: US01: 0.019” (0.5mm), US03: 0.039” (1mm)

Dead band: US01: 1.5” (3.8cm), US03: 4” (10.1cm)

Beam width: 2” (5cm)

Configuration: WebCal® PC Windows® USB® 2.0

Memory: Non-volatile

Supply voltage: 14-28 VDC

Loop resistance: 500 ohms @ 24 VDC

Signal output: 4-20mA, two-wire

Signal invert: 4-20mA or 20-4mA

Signal fail-safe: 4mA, 20mA, 21mA, 22mA, hold last

Process temp.: F: -40º to 176º, C: -40º to 80º

Temp. comp.: Automatic

Ambient temp.: F: -31º to 140º, C: -35º to 60º

Pressure: 30 psi (2 bar)

Enclosure rating: Type 6P (IP68)

Encl. material: Polypropylene

Transducer type: Reflective

Transducer mat.: Polyvinylidene fluoride

Cable jacket mat.: Polyvinyl Chloride

Cable type: 4-conductor, shielded

Cable length: 48” (1.2m)

Process mount: -0001: 2” NPT, -0011: 2” G

Mount gasket: -0001: N/a, -0011: Viton®

Classification: Intrinsically safe

Approvals: CSA for Canada: Class I, Division 1, Groups A, B, C and D T4; Class II, Division 1, Groups E, F and G T4; Class III, T135C; Ex ia IIC T4 Ga; Ex ia IIIC, T135C Da; CSA for U.S.: Class I, Division 1, Groups A, B, C and D T4; Class II, Division 1, Groups E, F and G T4; Class III, T135C; Class I, Zone 0, IIC AEx ia T4 Ga; Class II, Zone 20, IIIC AEx ia, T135C Da

Entity parameters: Install per control drawing #610125

Compliance: CE, RoHS


If you want help in selecting a sensor for your application, please submit a Level Questionnaire. An engineer will review your requirements and suggest a product solution via email.



Processing Magazine selected Flowline to receive their Breakthrough Product of the Year Award for our EchoPod and EchoTouch reflective ultrasonic sensors that provide reliable level measurement in condensing environments. See how.