Inline sound velocity sensor:
L-Sonic
- Concentration measurement, interface detection, and product identification
- For use in hazardous environments, i.e. chemical industry, and hygiene applications in the beverage and pharma industries
- Available in e.g. SST, Hastelloy BC1, rhodium plating, and more
- Easy integration, no maintenance, no consumables required
L-Sonic tells a story: a 30-year story of sound velocity sensor development at Anton Paar, culminating in the sleek L-Sonic 5100/6100 series, which delivers pin-point accuracy and constant quality control. The L-Sonic 5100 has a fork-type senor, the L-Sonic 6100 a tube-type sensor. Use them for inline concentration measurements, interface detection, or product identification. And rest assured: the sensors continuously monitor the product quality of liquids during production.
Key features

L-Sonic: compact, stand-alone, supremely accurate
The L-Sonic series’ digital signal processing produces remarkable repeatability of 0.005 m/s (fork type). And a temperature-compensated crystal oscillator provides a measurement time basis of phenomenal exactitude.
- Measurements uninfluenced by changes in pressure, flow rate, and viscosity
- High tolerance to bubbles
- Applicable for interface detection or product identification (fork-type sensor)
- Ideal for OCR measurement (tube-type sensor)

The right instrument for demanding applications and hazardous environments
The L-Sonic sensors can be applied to a wide range of samples and are resistant to aggressive media because their wetted parts (L-Sonic 5100) comprise a variety of different materials. The sensor is suited to hazardous environments, including those where there is a risk of explosion, and to demanding hygiene applications in the beverage and pharmaceutical industries. L-Sonic’s modularity means easy and cost-efficient integration. The tube-type sensor L-Sonic 6100 can be directly installed in small pipes, so the entire flow passes through the sensor, and the fork-type sensor L-Sonic 5100 is ideal for insertion into large pipes or tanks. Anton Paar’s L-Sonic is versatile and resilient. Its solutions are comprehensive and customized across industry:
- Hazardous environments (e.g. chemical industry)
- Hygiene applications (e.g. beverages, pharma, automotive)
- Full flow, inline, bypass, or tank installation

Save time: quick installation and start-up; no maintenance needed
With these sensors, you’ll save a ton of time. Pre-configured and adjusted in the factory, they come with the right setup and integrated application formulas – installation, start-up, and commissioning are quick, no on-site adjustments, maintenance, or consumables are needed.

An Anton Paar measuring solution – tailored to your specific needs
Anton Paar draws from our comprehensive database and application know-how to give you the information you need to measure the concentration of your liquids precisely. In our in-house laboratory we measure your samples and develop the formula best suited to your needs. We identify the ideal measuring method (density, sound velocity, or refractive index) for your sample, as well as the perfect concentration and temperature range.
No matter which industry you’re in, we help you determine the concentration of liquids accurately and efficiently. L-Sonic is the right choice for the chemicals, beverages, and petroleum sectors, and more.
Technical specifications
L-Sonic 5100 | L-Sonic 6100 | |
Measuring range | 800 m/s to 2500 m/s | 200 m/s to 1560 m/s |
Material of the wetted parts | Stainless Steel 1.4404 (316L) HASTELLOY® HYBRID-BC1® alloy Monel 400 Rhodium-coated Fork length: 56 mm 125 mm Customer-specific | Stainless Steel 1.4404 (316L) |
Accuracy in adjusted range: | ||
Reproducability sound velocity | 0.1 m/s | |
Reproducability temperature | 0.02 °C | |
Repeatability | 0.005 m/s | 0.01 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 specification | up to 70 bar @ 125 °C or 100 bar @ 50 °C |
Recommended flow rate | 0.5 to 6 m/s | 50 to 700 L/h |
Communication | Pico 3000:
mPDS 5:
| |
Process connections | VARIVENT® N VARIVENT® G DIN 11851 EN 1092-1 ANSI B16.5 | Tube end: OD 12 mm |
Dimensions: 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
- More than 350 manufacturer-certified technical experts worldwide
- Qualified support in your local language
- Protection for your investment throughout its lifecycle
- 3-year warranty
Documents
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Beverage | Beer | Brewhouse Extract Monitoring Application Reports
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Beverage | Beer | Complete your Beer Analysis Application Reports
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Beverage | Spirits | Complete your Spirits Analysis Application Reports
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Chemistry | Automatic product identification during unloading Application Reports
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Chemistry | Concentration Measurement Application Reports
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Chemistry | H2SO4 | Process Measurement of H2SO4 from 0 to 110 % Application Reports
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Chemistry | NaOH | Online concentration measurement of binary NaOH solutions Application Reports
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Food | Inline NaCl Brine Concentration Measurement in the Food Industry Application Reports
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From Measuring Result to Concentration - Using and Creating Quantities Application Reports
Consumables
Consumables
To find out if you can purchase online from your location, check the online availability below.
If you do not find the item you require, please contact your Anton Paar sales representative.

O-RING 60x3 EPDM 70 FDA COMPLIANT
L-Sonic 5100 | 6100