Nexisense Online Density Meter: Comparison of Side-mounted, Insertion and Pipeline Installation Solutions and Engineering Application Guide

The Nexisense online density meter series adopts the mature differential pressure measurement principle and is specially optimized for continuous density monitoring of high-viscosity, non-Newtonian fluids and media containing solid particles. It provides three typical installation forms: side-mounted, insertion and pipeline type for different working conditions, meeting the process control needs of petrochemical, pharmaceutical, food processing, sewage treatment, papermaking slurry and other industries. The device supports standard 4-20mA/HART and RS485 Modbus RTU output, and can seamlessly access DCS, PLC and industrial IoT platforms to realize multi-variable associated control of density value with temperature, pressure and flow.

Comparison of Three Installation Methods and Applicable Working Conditions

Insertion Density Meter is suitable for large storage tanks, sedimentation tanks, reaction kettles and other open or large-volume containers. The probe is directly immersed into the medium, and the upper and lower pressure-sensing diaphragms must be completely submerged in the liquid. Vertical installation is required to eliminate the influence of air bubbles and temperature gradients. Typical applications include density stratification monitoring of crude oil storage tanks, sludge concentration control in sewage treatment aeration tanks, and uniformity detection of food syrup storage tanks.

Pipeline Density Meter is specially designed for flow pipelines. The instrument body is connected in series in the process pipeline, requiring the pipeline to always maintain a full pipe state, with liquid flow velocity ≤4 m/s. It is recommended that the flow direction is from bottom to top to facilitate exhaust. It is suitable for continuous production pipelines, such as lubricating oil blending lines, paint conveying pipelines, papermaking white liquor/black liquor circulation systems, and pharmaceutical intermediate pipelines.

Side-mounted Density Meter is installed on the side of the tank or pipeline through side wall flange or threaded interface. The two pressure-sensing diaphragms must be located on the same vertical line and completely covered by the medium. It is suitable for small and medium-sized storage tanks, buffer tanks, and metering tanks, especially for scenarios where the medium is prone to sedimentation or contains air bubbles, such as fuel oil tanks, colloidal solution storage tanks, and sewage treatment regulating tanks.

Typical Application Scenarios and Project Cases

In the petrochemical field, Nexisense pipeline density meters are often used for online monitoring of heavy oil density at the bottom of atmospheric towers. Combined with flow meters, they achieve precise mass flow control and reduce blending tank ratio deviation. In the pharmaceutical industry, insertion installation is mostly used in crystallization tanks and liquid preparation tanks to track changes in mother liquor density in real time, optimizing crystallization yield and product quality consistency.

Sewage treatment plants generally use side-mounted density meters in regulating tanks and thickening tanks to monitor sludge concentration and link with screw pump speed to achieve automatic sludge discharge control. Typical projects include the renovation of a crude oil storage area in a large refining and chemical enterprise, where 38 side-mounted density meters were deployed and connected to the enterprise PI system. The density measurement repeatability is better than ±0.0005 g/cm³, reducing the frequency of manual sampling analysis by about 85% annually. In another pharmaceutical intermediate workshop in South China, insertion density meters were used in conjunction with Modbus TCP and host computer integration to achieve batch density trend traceability, significantly reducing the batch rework rate caused by density fluctuations.

Selection Guide

• Medium Characteristics: Viscosity >500 cP or solid content >5% prefer insertion or side-mounted type; continuous flow with stable flow velocity (<4 m/s) recommends pipeline type.

• Container/Pipeline Form: Large open tanks/sedimentation tanks select insertion type; small and medium storage tanks select side-mounted type; flow pipelines above DN50 select pipeline type.

• Accuracy and Range: Conventional process control uses ±0.001 g/cm³ accuracy, range 0.6–2.0 g/cm³; high-precision batching selects ±0.0005 g/cm³ model.

• Output and Communication: Prefer 4-20mA+HART for traditional control systems; RS485 Modbus RTU or PROFIBUS PA is selected for remote diagnosis and parameter configuration.

• Material and Protection: 316L + Hastelloy C-276 is suitable for corrosive media; explosion-proof type (Ex d IIC T6 Gb) is used in hazardous areas.

Integration and Installation Precautions

General Requirements All installation forms must be installed vertically with inclination ≤5°; avoid areas with strong vibration, drastic temperature changes and strong electromagnetic interference; complete zero point/range calibration before commissioning and input medium reference density and temperature compensation coefficients.

Insertion-specific Precautions Upper and lower diaphragms must be completely submerged; install the probe with the back facing the flow direction; stay away from agitator vortex areas and inlet/outlet ports; not recommended to install directly on flow pipelines.

Pipeline-specific Precautions The pipeline must operate with full pipe, flow velocity ≤4 m/s; recommend bottom inlet and top outlet flow direction; straight pipe sections before and after are recommended ≥5D (D is the inner diameter of the pipeline).

Side-mounted-specific Precautions Installation height must ensure both diaphragms are above the minimum liquid level; avoid thick sediment layers or scum covering the diaphragms inside the tank; the medium must not freeze or be in long-term overheating (>150℃) contact with the diaphragms.

When integrating the system, priority should be given to using HART protocol for remote parameter configuration and diagnosis, or RS485 Modbus RTU for multi-instrument bus connection. It is recommended to set density overrun alarms linked with pump and valve control, and perform on-site wet calibration verification regularly (every 6 months).

OEM Customization and Bulk Supply Advantages

Nexisense supports OEM labeling production and can customize probe length, diaphragm material, flange standard, range interval, communication protocol and display interface language according to project requirements. Bulk supply provides tiered pricing, long-term supply agreements, special installation bracket/protective cover development and on-site debugging guidance. The delivery package includes complete installation manuals, calibration certificates, communication protocol documents and SDK examples, helping system integrators quickly respond to tender projects in chemical, pharmaceutical, environmental protection and other industries.

Frequently Asked Questions (FAQ)

Conclusion

Nexisense online density meter has proven its engineering applicability in multiple chemical, pharmaceutical and environmental protection projects with its flexible installation forms, stable differential pressure measurement and seamless system integration capabilities. System integrators, EPC contractors and process control engineers can contact us to obtain detailed selection manuals, prototype testing arrangements and project cooperation solutions to jointly optimize industrial process density control levels.