The general purpose ultrasonic level transmitter provides continuous level measurement up to 32.8’ (10m) with a 4-20 mA signal output, and is configured via our free Webcal software. This non-contact liquid level sensor is ideally suited for corrosive, ultrapure, sticky or dirty liquids, and is broadly selected for bulk storage, day tank, lift station and process tank level applications.


  • Offered in 4 measurement ranges from 9.8’ (3m) to 32.8’ (10m)
  • Configuration is fast and easy via WebCal software and USB adapter
  • Narrow 2” or 3” beam width for applications with limited space
  • Short 4” or 8” dead band maximizes the filling capacity of the tank
  • PVDF transducer and NEMA 4X PC enclosure for corrosive liquids
  • Automatic temperature compensation for accurate measurement


P/N Description From
LU23-40 5.5m (18′), 2″ NPT, conduit w/o Fob $685.00
LU23-41 5.5m (18′), 2″ NPT, conduit w/Fob $730.00
LU23-50 5.5m (18′), 2″ G, conduit w/o Fob $690.00
LU23-51 5.5m (18′), 2″ G, conduit w/Fob $735.00
LU27-40 3m (9.8′), 1″ NPT, conduit w/o Fob $585.00
LU27-41 3m (9.8′), 1″ NPT, conduit w/Fob $630.00
LU27-50 3m (9.8′), 1″ G, conduit w/o Fob $590.00
LU27-51 3m (9.8′), 1″ G, conduit w/Fob $635.00
LU28-40 8m (26.2′), 2″ NPT, conduit w/o Fob $785.00
LU28-41 8m (26.2′), 2″ NPT, conduit w/Fob $830.00
LU28-50 8m (26.2′), 2″ G, conduit w/o Fob $790.00
LU28-51 8m (26.2′), 2″ G, conduit w/Fob $835.00
LU29-40 10m (32.8′), 2″ NPT, conduit w/o Fob $885.00
LU29-41 10m (32.8′), 2″ NPT, conduit w/Fob $930.00
LU29-50 10m (32.8′), 2″ G, conduit w/o Fob $890.00
LU29-51 10m (32.8′), 2″ G, conduit w/Fob $935.00


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: LU27: 4” to 9.8’ (10cm to 3m), LU23: 8” to 18.0’ (20cm to 5.5m), LU28: 8” to 24.6’ (20cm to 8m), LU29: 8” to 32.8’ (20cm to 10m)

Accuracy: ± 0.2% of range

Resolution: LU27: 0.019” (0.5mm), LU23: 0.039” (1mm), LU28/29: 0.079” (2mm)

Dead band: LU27: 4” (10cm), LU23/28/29: 8” (20cm)

Beam width: LU27: 2” (5cm), LU23/28/29: 3” (7.6cm)

Configuration: WebCal® PC Windows®, USB 2.0

Memory: Non-volatile

Supply voltage: 24 VDC (loop)

Consumption: 0.5W

Loop resistance: 500 ohms @ 24 VDC

Signal output: 4-20 mA, two-wire

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

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

Process temp.: F: -4º to 140º, C: -20º to 60º

Temp. comp.: Automatic

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

Pressure: MWP = 30 PSI (2 bar)

Enclosure rating: NEMA 4X (IP65)

Encl. material: Polycarbonate

Trans. material: PVDF

Cable jacket mat.: Polyurethane

Cable type: 4-conductor, shielded

Process mount: LU27: 1” NPT (1” G), LU23/28/29: 2” NPT (2” G)

Mount gasket: Viton®

Classification: General purpose

Compliance: CE, RoHS

Approvals: cFMus


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.