MS-421 Online Viscometer

Product Introduction

The MS-421 provides continuous viscosity measurement for selected industrial liquids using vibration-based sensing technology.
Designed for direct installation in pipelines, tanks and process vessels, it provides real-time viscosity data for process monitoring, quality control and operating adjustment.

Core Information

Detection Target	Typical Applications
Viscosity	Process Pipelines · Mixing Tanks · Reactors · Circulation Lines · Process Vessels

Product Overview

Overview

The MS-421 is an online viscometer for continuous measurement of selected industrial liquids.
Installed directly in a pipeline, tank or process vessel, the sensor continuously evaluates changes in the sensing probe’s vibrational damping and related response when interacting with the process liquid.
An application-specific calibration converts the measured response into a viscosity value. Continuous measurement provides faster process information than periodic offline sampling, helping operators identify viscosity changes earlier and improve process consistency.
For non-Newtonian fluids, the reported value represents apparent viscosity under the sensor’s measurement and process conditions. Shear behaviour and the laboratory reference method must be considered during application evaluation and calibration.

Application Scope

Suitable for Selected:
Petroleum products and industrial oils
Chemical and polymer liquids
Resins, adhesives and coatings
Paints and inks
Pharmaceutical process liquids
Food and beverage liquids
Selected high-temperature process fluids

Detection Principles

The sensing probe is maintained in a controlled vibration state while immersed in the process liquid. Interaction with the liquid changes the probe’s vibrational damping and related response. The instrument evaluates this response through an application-specific calibration to provide a continuous viscosity value. Because the vibration response may also be affected by density, temperature and process conditions, applications involving significant changes in composition or density require separate evaluation.

Key Advantages

Continuous Process Measurement：Provides continuous viscosity information directly from the process, helping operators identify changes between laboratory tests and respond more quickly.

Wide Measurement Range：Supports viscosity measurement across a wide range of selected industrial liquids, subject to fluid characteristics and application calibration.

Industrial Sensor Design：The vibration-based sensor has no rotating measurement components, helping reduce mechanical wear. Periodic inspection and cleaning may still be required depending on the fluid’s fouling and buildup tendency.

Process Integration：Provides 4–20 mA output and Modbus RTU communication for connection with PLC, DCS and industrial monitoring systems.

Product Parameters

Parameter	Specification
Measurement Principle	Vibration-based viscosity measurement
Measurement Parameter	Viscosity
Measurement Range	0–1,000,000 mPa·s; achievable range depends on fluid characteristics and application calibration
Accuracy	Up to ±0.5%, application-dependent
Process Temperature	0°C to +100°C standard; up to +300°C optional
Process Pressure	Application-dependent; high-pressure configurations up to 28 MPa
Wetted Material	316 stainless steel
Analog Output	4–20 mA
Communication	Modbus RTU
Power Supply	24 VDC

Optional Configuration

01 — Standard Configuration

Standard vibration sensor for continuous viscosity measurement in suitable pipelines, tanks and process vessels.

The standard configuration uses 316 stainless-steel wetted parts and supports a DN50/PN16 flange connection for suitable low-pressure applications.

02 — High-Temperature Configuration

Customized sensor configuration for selected processes operating above the standard temperature range and up to +300°C.

Final sensor structure, sealing material, insertion arrangement and process connection depend on the actual operating temperature and process medium.

03 — High-Pressure Configuration

Customized configuration for selected high-pressure applications up to 28 MPa.

The allowable process pressure depends on the sensor construction, connection rating, sealing arrangement, process temperature and supplied configuration.

04 — Explosion-Protected Configuration

Available for selected hazardous-area applications.

The enclosure, electrical arrangement and explosion-protection marking must be confirmed according to the certification supplied with the ordered configuration.

Application Engineering

Evaluate the MS-204 for Your Process

Share your material characteristics, moisture range, process conditions and installation requirements with MOSYE application engineers. We will evaluate the appropriate probe, process connection and measurement configuration for your application.

Request Application Evaluation