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Part number

Sound velocity sensors:
L‑Sonic 5100/6100

Sound velocity sensor for inline concentration measurement

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30 years of experience have substantially contributed to the development of the new generation of sound velocity sensors. The new sensors offer two types of sensing elements: a fork-type L-Sonic 5100 and a tube-type L-Sonic 6100.

They are ready for various applications, such as inline concentration measurements, interface detection, or product identification. The sensors continuously monitor the product quality of liquids during production. The concentration is directly calculated and can be displayed by the optional HMI of the new Pico 3000 transmitter.

An outstanding repeatability of 0.005 m/s (fork type) is achieved by digital signal processing - without averaging the signals. A temperature compensated crystal oscillator provides the most accurate time base to measure.

Key features

Stable measurement by digital signal processing

Stable measurement by digital signal processing

A powerful microcontroller generates and shapes the sound pulses and performs digital signal processing on the received response. The implemented algorithms ensure measurements with the highest accuracy.

  • The smallest changes in the medium are recognized and calculated
  • Measurements are virtually uninfluenced by changes in pressure, flow rate, and viscosity

The prevention of errors in the measurement is supported by:

  • Low thermal inertia
  • High tolerance to bubbles
L-Sonic stands for flexibility and efficiency in integration

L-Sonic stands for flexibility and efficiency in integration

L-Sonic supports easy and cost-efficient integration due to its modularity. The tube-type sensor L-Sonic 6100 can be directly installed in small pipes so the entire flow passes through the sensor whereas the fork-type sensor L-Sonic 5100 is ideal for insertion into large pipes or tanks using:

  • VARIVENT® or milk pipe flange connections for hygienic applications
  • EN or ANSI flange connections, which can be tailored to customer requirements
  • Adaptable fork lengths which can be customized to existing circumstances

The L-Sonic 5100 with VARIVENT® connection is EHEDG certified and thereof suitable for hygienic applications in the beverage and pharmaceutical industry.

Low cost for a lean solution – L-Sonic as a complete stand-alone instrument

Low cost for a lean solution – L-Sonic as a complete stand-alone instrument

By including the optional Pico 3000 process instrumentation controller, which can be equipped with a Pico 3000 HMI (human machine interface), no additional evaluation and/or operating units are required. That saves space and enables data management directly at the point of measurement.

  • Human machine interface with capacitive keys
  • Common industrial fieldbus standards supported
  • Backup and restore function
  • Data and error log function
  • USB interface at the electronics housing for configuration with a laptop
The right instrument for demanding applications

The right instrument for demanding applications

L-Sonic is prepared for use in hazardous areas. Due to its wetted materials it is suitable to cover a wide range of applications from material-friendly, non-corrosive medias to highly aggressive acids and bases.

  • Stainless steel 1.4404 for hygienic applications in the food and beverage industry as well as special applications in chemistry
  • HASTELLOY® HYBRID-BC1® alloy with excellent corrosion resistance for, e.g. sulfuric acid
  • Rhodium coating with a scratch-resistant surface and best resistance for the measurement of extremely aggressive chemicals
  • Monel 400 for strong alkaline solutions
Designed for a long working life and minimum of follow-up costs

Designed for a long working life and minimum of follow-up costs

The high wall thickness of the electronics housing and its strong direct connection with the sensing element forms a robust unit which enables the sensor to have a long working life under harsh conditions.

L-Sonic sensors:

  • have a robust electronics housing made of stainless steel
  • are maintenance-free
  • do not require any consumables

Technical specifications

L-Sonic 5100 L-Sonic 6100
Measuring range 800 m/s to 2500 m/s 200 m/s to 1000 m/s
Material of the wetted parts Stainless Steel 1.4404 (316L)
Monel 400

Fork length:
56 mm
125 mm
Stainless Steel 1.4404 (316L)
Accuracy in adjusted range:
Reproducability sound velocity0.1 m/s
Reproducability temperature0.02 °C
Repeatability 0.005 m/s0.01 m/s
Process temperature -25 °C to 125 °C
CIP/SIP temperature and duration 145 °C for max. 30 min.
Ambient temperature
(for non-Ex versions)
-25 °C to 65 °C without HMI
-20 °C to 55 °C with HMI
Process pressure absolute According to flange
up to 70 bar @ 125 °C or
100 bar @ 50 °C
Recommended flow rate >0 m/s to 6 m/s
Communication Pico 3000:
  • Analog
  • HART
  • Modbus RTU

mPDS 5:
  • Devicenet
  • Ethernet/IP
  • Modbus TCP
  • I/O Board
Process connections VARIVENT® N
DIN 11851
EN 1092-1
ANSI B16.5
Tube end:
OD 12 mm
Non-Ex version (L x W x H)
Ex version (L x W x H)

Depending on model
Depending on model

150 mm x 145 mm x 175 mm
160 mm x 160 mm x 190 mm

Explosion-proof versions according to ATEX / IECEx / FM / UL / CSA

Anton Paar Certified Service

The Anton Paar quality in service and support:
  • More than 350 manufacturer-certified technical experts worldwide
  • Qualified support in your local language
  • Protection for your investment throughout its lifecycle
  • 3-year warranty
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Part number: 74911