Choose Lonnmeter for accurate and intelligent measurement!

Online Viscometer — LONN-DN60 Integrated Viscosity Meter

LONN-DN60 online viscometer with integrated sensor and transmitter. 0-5,000,000 cP range, Ex d IIC T6, 4-20mA + RS485. Wide temperature 0-300C. Built-in display.

  • Measurement Principle: Tuning fork vibration
  • Viscosity Range: 0 – 5,000,000 cP (segment calibratable)
  • Viscosity Accuracy: ±3.0% of reading
  • Explosion Protection: Ex d IIC T6 (flameproof)
  • Output: 4-20mA + RS485 Modbus RTU
  • Power Supply: 24V DC
  • Medium Temperature: 0°C to +300°C
  • Protection Class: IP67 / IP68 (probe)

The LONN-DN60 online viscometer is an integrated industrial viscosity meter that combines sensor and transmitter in a single compact enclosure — built for continuous, real-time viscosity monitoring in demanding process environments. With a wide viscosity range spanning 0 to 5,000,000 cP and a process temperature capability up to +300°C, this inline viscometer handles everything from low-viscosity solvents to highly viscous resins, bitumen, and polymer melts.

The LONN-DN60 uses the proven tuning fork vibration principle: a piezoelectric element drives the sensor fork at its resonant frequency, and the liquid’s viscosity and density affect the damping of that vibration. The onboard microprocessor converts this frequency shift into a viscosity reading displayed locally on the backlit LCD screen and transmitted via 4-20mA and RS485 Modbus RTU simultaneously. No moving parts, no consumables, no radioactive sources — just reliable, continuous process viscometer performance.

The integrated design means one device, one process penetration, one calibration — simpler installation than split-body systems, with the display always accessible at the mounting point. The LONN-DN60 industrial viscometer is engineered for chemical plants, refineries, polymer processing, food production, and any facility that needs accurate online viscosity data for quality control and process optimization.

Why Choose the LONN-DN60 Online Viscometer?

Integrated Design — Simpler Installation, Lower Cost

The LONN-DN60 combines the sensor and transmitter in a single rugged housing — no separate transmitter enclosure, no additional cable runs, no complex wiring between sensor and electronics. This integrated viscosity meter mounts directly into your process line or vessel, with the LCD display readable right at the installation point. For facilities that lack dedicated instrument rooms or have limited space near the process connection, the LONN-DN60 eliminates the separate transmitter problem entirely. One process penetration, one device, one calibration — reducing both initial installation cost and ongoing maintenance burden.

Wide Viscosity Range — From Solvents to Asphalt

Many industrial processes run across a wide viscosity spectrum — different product grades, seasonal temperature variations, or batch-to-batch raw material changes all shift fluid consistency. The LONN-DN60 online viscometer covers 0 to 5,000,000 cP in a single instrument, with field-calibratable measurement segments that let you focus accuracy on your actual operating range. Whether you are measuring thin hydraulic oils at 10 cP or thick bitumen at 500,000 cP, the LONN-DN60 delivers the range you need without swapping sensors between batches.

High Temperature Capability — Up to 300°C

Processes running at elevated temperatures — distillation columns,熔融聚合物 pipelines, hot oil systems, and aseptic food processing — demand sensors that can handle heat. The LONN-DN60 handles process temperatures from 0°C to +300°C at the sensor, making it suitable for applications that exceed the range of most competing inline viscometer products. The stainless steel sensor and vibration element are rated to +450°C, providing a safety margin for peak temperature excursions.

Flameproof Certification for Hazardous Areas

The LONN-DN60 carries Ex d IIC T6 flameproof certification, meaning the enclosure is designed to contain any internal ignition and prevent it from propagating to the surrounding explosive atmosphere. This makes the LONN-DN60 online viscometer suitable for Zone 1 and Zone 2 hazardous areas in oil refineries, chemical processing plants, gas facilities, and pharmaceutical manufacturing where flammable vapors or gases are present.

Dual Output — 4-20mA and RS485 Modbus Together

Process plants use both analog and digital control systems, often side by side. The LONN-DN60 delivers simultaneous 4-20mA analog output and RS485 Modbus RTU digital communication from the same instrument — connect the 4-20mA to your DCS or PLC analog input while using Modbus for digital trending, remote configuration, and data logging. No signal converters, no duplicated hardware. The on-site menu system allows operators to configure measurement ranges, set damping, and perform calibration adjustments directly through the 4-button interface without removing the instrument from service.


Technical Specifications — Online Viscometer

Specification Value
Measurement Principle Tuning fork vibration frequency analysis
Viscosity Range 0 – 5,000,000 cP (segment calibratable)
Viscosity Accuracy ±3.0% of reading
Viscosity Repeatability ±1%
Temperature Compensation Automatic, built-in PT100
Medium Temperature Range 0°C to +300°C
Sensor Max Temperature +450°C
Max Working Pressure < 6.4 MPa
Explosion Protection Ex d IIC T6 (flameproof, 隔爆)
Signal Output 4-20mA + RS485 Modbus RTU
Power Supply 24V DC
Display Backlit LCD: viscosity, temperature, loop current
On-Site Configuration Menu-driven via 4-button keypad
Wetted Materials 316L stainless steel
Process Connection Thread M50×2 (standard); Flange DN4.0 PN4.0 (optional)
Protection Class IP67 / IP68 (probe); IP65 (display housing)
Cable Entry M20×1.5 cable gland

The LONN-DN60 online viscometer complements the LONNMETER family of process instruments. For applications requiring sensor electronics separation from hot or vibrating process environments, the LONN-DN100 split type viscometer offers a remote transmitter configuration. For non-nuclear density measurement, the LONN-700S tuning fork density meter provides an ideal companion solution on the same fluid line.


Online Viscometer Applications by Industry

Chemical & Petrochemical Processing

Chemical reactors, resin polymerization vessels, and solvent recovery systems all depend on continuous viscosity measurement to track reaction progress, verify product quality, and trigger phase changes. The LONN-DN60 handles process temperatures up to +300°C and aggressive media including acids, caustics, and organic solvents with its 316L stainless steel wetted path. The inline viscometer mounts directly into the reactor or pipeline, feeding real-time data to the DCS for closed-loop process control.

Key chemical applications:

  • Polymerization reaction endpoint detection via viscosity rise
  • Solvent concentration tracking in distillation overheads
  • Acid and caustic solution viscosity monitoring
  • Resin and adhesive viscosity during synthesis
  • Catalyst activity monitoring in refinery processes

Oil & Gas — Refining & Petrochemical

Crude oil refineries process crude oils of wildly varying viscosity — from light condensates at single-digit cP to heavy fuel oils at hundreds of thousands of cP. The LONN-DN60 covers this entire range with segment calibration, making it suitable for custody transfer monitoring, blend optimization, and process heater firing control. The Ex d viscometer is certified for installation in Class I Division 1 hazardous areas common in refinery process units.

Oil & gas applications:

  • Crude oil viscosity at pipeline receiving and storage tanks
  • Vacuum residue viscosity monitoring in FCC units
  • Fuel oil viscosity for burner optimization (heated systems)
  • Lubricating oil viscosity at blending facilities
  • Asphalt viscosity at bitumen loading terminals

Polymer Processing — Plastics, Resins & Rubber

Polymer melts are among the most challenging fluids to measure — extremely viscous, often above 10,000 cP, and processed at temperatures up to 300°C. The LONN-DN60 process viscometer is designed for these conditions, with the sensor rated to +450°C and a viscosity range covering standard polymers from polypropylene to high-density polyethylene. Viscosity data from the LONN-DN60 helps operators maintain consistent melt flow index and detect batch variations before they become quality escapes.

Polymer applications:

  • Melt viscosity monitoring in extrusion lines
  • Polymerization reactor viscosity tracking
  • Resin solution viscosity during synthesis
  • Rubber mastic viscosity in tire manufacturing
  • Adhesive viscosity in hot melt application

Food & Beverage Processing

From thin sugar syrups to thick dairy creams, the food industry needs online viscosity measurement for consistency control, standardization, and regulatory compliance. The LONN-DN60 with 316L stainless steel wetted parts and CIP-compatible design handles food-grade process fluids including sugar solutions, starch suspensions, chocolate, oils, and dairy products. The integrated display allows operators to verify product quality directly at the processing line.

Food applications:

  • Sugar syrup viscosity during evaporation and crystallization
  • Chocolate viscosity monitoring for tempering control
  • Edible oil viscosity at refining and packaging
  • Tomato paste and sauce viscosity at concentrate processing
  • Starch slurry viscosity in sweetener production

Pharmaceutical & Biotechnology

Pharmaceutical manufacturing requires precise control of fluid properties during API synthesis, formulation, and final product filling. The LONN-DN60 industrial viscometer provides real-time viscosity data for batch consistency verification and regulatory documentation. The field-configurable measurement range accommodates different solvent systems and concentration profiles across product campaigns, while the RS485 Modbus output integrates with pharmaceutical data historian systems for 21 CFR Part 11 compliance.

Pharmaceutical applications:

  • API solution viscosity during crystallization
  • Gel and cream viscosity at filling lines
  • Syrup viscosity for oral solution standardization
  • Fermentation broth viscosity monitoring
  • Vial filling consistency verification

Installation Guidelines for Online Viscometer

For reliable performance from the LONN-DN60 inline viscometer, follow these installation recommendations:

  1. Mounting orientation: Install the sensor with the fork tines oriented perpendicular to the flow direction, in a section of pipe with full pipe flow — avoid partially filled pipes or gravity drainage lines where air pockets can form around the sensor
  2. Temperature at display: Ensure the ambient temperature at the display housing does not exceed the instrument rating — in high-temperature process areas, consider a sun shade or remote mounting bracket to protect the electronics from direct heat exposure
  3. Process pressure seal: Use the specified torque and sealing gasket when installing the process connection — over-tightening can deform the sensor; under-tightening risks process fluid leakage at pressure
  4. Electrical connections: Route power and signal cables through the sealed cable glands — ensure both glands are securely tightened to maintain IP65 (display housing) and IP67/IP68 (probe) ratings
  5. EMI protection: Keep the instrument cable at least 3 meters from variable frequency drives and high-power motors; use shielded cable if the installation is in a high-electromagnetic-noise environment
  6. Initial calibration: Perform on-site calibration using a reference standard or known-viscosity fluid before putting the instrument into service — the LONN-DN60 supports menu-driven calibration with multiple calibration points

Why This Non-Nuclear Online Viscometer Matters

The LONN-DN60 uses the tuning fork vibration principle for continuous viscosity measurement — no radioactive sources, no gamma radiation, no licensing bureaucracy. Alternative technologies such as nuclear gauge viscosity measurement (using Am-241 or Cs-137 sources) impose ongoing compliance burdens:

  • Annual regulatory inspections and source leak testing
  • Radiation safety training for all maintenance personnel
  • Licensed disposal procedures when sources reach end-of-life
  • Shielding design requirements that add cost and weight
  • Special transport and storage protocols

The non-nuclear online viscometer approach eliminates all of these costs and risks. The LONN-DN60 delivers reliable continuous viscosity measurement with no regulatory overhead, no safety program, and no end-of-life disposal complexity — the practical choice for modern process industries.


Frequently Asked Questions

Q: What is the difference between the LONN-DN60 integrated viscometer and the LONN-DN100 split type viscometer?

A: The LONN-DN60 is an integrated viscosity meter with sensor and transmitter in a single housing — simpler installation, lower cost, best for standard process conditions. The LONN-DN100 split type viscometer separates the transmitter from the sensor via a cable assembly, which is preferred when process temperature at the mounting point exceeds the electronics rating, when vibration at the pipe is severe, or when the display needs to be positioned at eye level away from the process connection.

Q: What viscosity range does the LONN-DN60 cover?

A: The LONN-DN60 covers 0 to 5,000,000 cP. The measurement range is field-calibratable in segments — for example, you can configure the instrument for 0-1,000 cP, 1,000-10,000 cP, or 10,000-100,000 cP to improve accuracy at your actual operating point.

Q: How does the LONN-DN60 handle high process temperatures?

A: The LONN-DN60 sensor tolerates process temperatures from 0°C to +300°C continuously, with a maximum sensor rating of +450°C for short-duration excursions. The display housing is rated to the stated ambient temperature range. For processes above +300°C, consult the factory for extended temperature configurations.

Q: Does the LONN-DN60 need a separate transmitter?

A: No — the LONN-DN60 is a fully integrated viscosity meter with sensor, microprocessor, display, and signal output all housed in one unit. The 4-20mA and RS485 Modbus outputs are built into the instrument, requiring only 24V DC power and a connection to your control system.

Q: Can the LONN-DN60 be installed in hazardous areas?

A: Yes. The LONN-DN60 is certified Ex d IIC T6 (flameproof, 隔爆), suitable for Zone 1 and Zone 2 hazardous areas where flammable gases or vapors are present. The flameproof housing prevents internal ignition from propagating to the surrounding atmosphere.

Q: What output signals are available on the LONN-DN60 ?

A: The standard configuration includes both 4-20mA analog output and RS485 Modbus RTU digital communication simultaneously. The 4-20mA can be scaled to your viscosity measurement range and connected directly to any DCS, PLC, or data logger that accepts analog input.

Q: Is the LONN-DN60 suitable for food or pharmaceutical applications?

A: Yes. The 316L stainless steel wetted parts are compatible with food contact and pharmaceutical process fluids. The instrument supports CIP (Clean-in-Place) procedures and can be configured for different product campaigns. For pharmaceutical applications, the RS485 Modbus output supports integration with data historian systems for batch record documentation.

Q: What installation connection does the LONN-DN60 use?

A: The standard process connection is a thread fitting (M50×2). An optional flange connection (DN4.0 PN4.0) is available. Both connections use 316L stainless steel as the wetted material for corrosion resistance.

Q: How does the LONN-DN60 compare to rotational viscometers?

A: Rotational viscometers use a rotating spindle immersed in the fluid — they require continuous power to maintain rotation and are prone to bearing wear and spindle fouling in dirty process fluids. The LONN-DN60 tuning fork viscometer has no moving parts (only the vibrating fork), consumes less power, and is more resistant to fouling and particle-laden fluids. It is purpose-built for continuous inline measurement rather than laboratory spot-checking.

Q: How often does the LONN-DN60 need calibration?

A: Under normal process conditions, the LONN-DN60 maintains accuracy for 12-24 months between calibrations. The field calibration function allows on-site adjustment using a reference standard without removing the instrument from the process line. For critical quality control applications, an annual calibration verification is recommended.


Request a Quote

Ready to add continuous online viscosity monitoring to your process? Contact our technical sales team for pricing, lead time, and application-specific configuration.

Inquiry Item Details
Product LONN-DN60 Online Viscometer (Integrated)
Process Connection □ Thread M50×2 □ Flange DN4.0 PN4.0 (specify)
Viscosity Range □ 0-100,000 cP □ 0-500,000 cP □ 0-5,000,000 cP □ Custom
Application (Brief description of your process medium and conditions)
Quantity ______ units
Target Price ______ USD/unit

📧 Email your inquiry to: anna@xalonn.com or Fill out our RFQ form

As a specialized split type density meter manufacturer with direct-from-factory pricing, LONNMETER provides complimentary application engineering support to ensure optimal model selection for your specific installation constraints. We don’t just sell instruments — we partner with your engineering team to deliver reliable measurement solutions.

Leave Your Message

Request for Quotation

Please provide your application parameters for a technical assessment and formal quote.