The LONN-700CM inline tuning fork density meter is a high-precision online density meter designed for continuous, real-time liquid density measurement and concentration monitoring in industrial processes. Engineered with a robust vibrating fork sensor, this tuning fork density meter delivers stable, accurate density readings across demanding applications — from corrosive chemicals in petrochemical plants to sugar solutions in food production lines.
Unlike bulky coriolis mass flow systems, the LONN-700CM vibrating fork density sensor installs directly into your pipeline via flange connection, requiring minimal straight pipe run and offering straightforward integration with existing DCS and PLC systems via 4-20mA output or RS485 Modbus protocol.
Key Benefits:
The LONN-700CM inline tuning fork density meter operates on a proven vibrating fork principle: an electronic circuit drives a pair of metal tuning forks to vibrate at their natural resonant frequency submerged in the process liquid. As the liquid density changes, the vibrational frequency shifts proportionally — denser liquids damp the vibration, while lower-density fluids allow faster oscillation. The instrument’s built-in temperature sensor applies automatic 20 ppm/°C compensation, calculating the corrected density value referenced to 25°C.
This continuous density measurement approach offers significant advantages over alternative technologies. Compared to an ultrasonic density analyzer, the tuning fork sensor performs better in clean, low-particulate liquids. Compared to a nuclear or radiometric densitometer, the LONN-700CM non nuclear density meter eliminates radioactive source licensing, safety inspections, and complex compliance procedures — making it the preferred solution for mines, chemical plants, and food facilities seeking a safer, lower-maintenance continuous density monitoring system.
A coriolis mass flow system achieves higher theoretical accuracy but demands more complex installation, larger pipe runs, and significantly higher cost. The LONN-700CM vibrating fork density sensor provides an ideal balance: solid industrial accuracy, easy inline installation, and a competitive price point backed by LONNMETER’s direct-from-factory guarantee.
| Parameter | Specification |
|---|---|
| Measurement Principle | Tuning fork vibration frequency |
| Density Range | 0 ~ 2 g/cm³ (0 ~ 2000 kg/m³) |
| Density Accuracy | ±0.002 g/cm³ |
| Density Repeatability | ±0.0001 g/cm³ |
| Concentration Range | 0 ~ 100% |
| Concentration Accuracy | ±0.25% |
| Temperature Coefficient | 20 ppm/°C (after calibration) |
| Process Temperature | Standard: -25°C ~ +120°C; Custom: -25°C ~ +150°C |
| Max Working Pressure | Standard: 2.5 MPa; Custom: 6.3 MPa |
| Wetted Materials | 316L SS, Hastelloy, Titanium, Zirconium (optional) |
| Fork Surface Treatment | Standard polish / PTFE coating / Electro-polish |
| Enclosure Rating | IP65, Aluminum alloy |
| Output Signals | 4-20mA + RS485 (Modbus RTU) |
| Max Medium Viscosity | 2000 cP |
| Particle Size Limit | <10 μm (recommended); 10-50 μm (limited use) |
| Max Suspended Solids | ≤40% |
| Max Gas Content | ≤20% |
| Power Supply | 24V DC |
| Display | LCD with backlight |
| Mounting | Flange connection (ANSI/DIN/JIS) |
This inline density meter handles crude oil density monitoring in pipeline transfer stations and fuel oil density tracking at refinery injection points. The Hastelloy-wetted version serves sulfuric acid concentration monitoring in alkylation units. For fuel quality control across the processing chain, continuous inline density measurement ensures consistent product quality and batch control.
The LONN-700CM is specified as a process density meter for hydrochloric acid, sodium hydroxide (caustic soda), methanol, ethanol, glycerin, and hydrogen peroxide processes. The Hastelloy or Zirconium material option provides reliable corrosive liquid density monitoring where aggressive media would damage standard stainless steel sensors.
For sugar concentration measurement, the LONN-700CM delivers precise brix monitoring in sugar refineries and beverage production. Sanitary-grade wetted parts make this a sanitary process density sensor for syrups, fruit juice concentration monitoring, and brewing process control. As a pharmaceutical process instrument, it monitors solvent density in alcohol extraction and API concentration processes.
The inline density meter configuration tracks sulfuric acid concentration in lead-acid battery formation and monitors lithium hydroxide concentration in electrolyte preparation — a critical quality control parameter for battery manufacturers.
Though optimized for cleaner media, the LONN-700CM handles light slurry concentration monitoring in pre-concentration circuits with careful particle sizing. For heavy slurry applications, consider the LONN-7000 series ultrasonic concentration meter as an alternative.
The online density meter monitors wastewater concentration in MVR evaporator concentrate streams and provides slurry density analysis for limestone-gypsum slurry in power plant scrubbers.
| Feature | Tuning Fork (LONN-700CM) | Ultrasonic Density Analyzer | Nuclear / Radiometric | Coriolis Mass Flow |
|---|---|---|---|---|
| Density Accuracy | ±0.002 g/cm³ | ±0.005 g/cm³ | ±0.001 g/cm³ | ±0.0001 g/cm³ |
| Installation | Inline flange | Inline / Clamp-on | Radiation shield | Large supports |
| Maintenance | Virtually maintenance-free | Low | High (radiation compliance) | Periodic tube cleaning |
| Safety | No radiation hazard | No radiation hazard | Radioactive source regulated | No radiation hazard |
| Cost | Medium | Medium | High | Very High |
| Best For | Clean liquids, chemicals, food | Slurries, opaque liquids | Mining, dredging, heavy slurry | Ultimate precision, custody transfer |
Choose the LONN-700CM if:
Consider alternative technologies if:
Q: How does a tuning fork density meter work?
A: The LONN-700CM operates on a proven vibrating fork principle: an electronic circuit drives a pair of metal tuning forks to vibrate at their natural resonant frequency submerged in the process liquid. As the liquid density changes, the vibrational frequency shifts with the density — this relationship is calibrated and temperature-compensated to produce accurate density readings in real time.
Q: What is the difference between a tuning fork density sensor and an ultrasonic density analyzer?
A: A tuning fork density sensor measures the damping effect of liquid on a vibrating fork, ideal for clean liquids. An ultrasonic density analyzer uses sound wave propagation speed, better suited for slurries and opaque media with higher suspended solids.
Q: Is the LONN-700CM a non nuclear density meter? Can it replace a nuclear densitometer?
A: Yes. The LONN-700CM is a non nuclear density meter that uses mechanical vibration technology — no radioactive source is required. It is a direct alternative for facilities looking to replace Berthold or other nuclear/radiometric density meters while eliminating radiation licensing and safety compliance burden.
Q: How do I calibrate the inline density meter?
A: The unit ships factory-calibrated. For field verification, immerse the tuning fork in a reference liquid of known density (e.g., distilled water = 1.000 g/cm³ at 25°C) and adjust the calibration offset via the LCD menu. We recommend annual recalibration for critical process applications.
Q: Can this online density meter measure concentration directly?
A: Yes. When the density-to-concentration relationship is known (e.g., sulfuric acid solutions, sugar/water Brix), we can pre-program the concentration curve so the outputs display directly as concentration %. Provide your media type and target concentration range when requesting a quote.
Ready to get pricing? Fill out our RFQ form with the following information:
Response time: Within 24 hours for standard configurations.
As a trusted process density meter manufacturer, LONNMETER supplies factory-direct pricing with full technical documentation — including detailed product datasheet, full specification sheet, and Modbus register map for every unit. The LONN-700CM Inline Tuning Fork Density & Concentration Meter exemplifies advanced technology in liquid density measurement. This industrial density meter operates as a vibrating fork density meter, providing precise and continuous density readings essential for various applications. With its robust density sensor, this non-nuclear density meter ensures reliable performance in challenging environments. Designed for seamless integration, the inline density meter serves as an effective density analyzer, enabling real-time monitoring and enhanced process efficiency.
Please provide your application parameters for a technical assessment and formal quote.