Non-contact Density Measurement for Challenging Processes
The VEGA MINITRAC 31 is a radiometric sensor designed for continuous density measurement of liquids and bulk solids. Unlike conventional density measurement technologies that require direct contact with the medium, MINITRAC 31 is installed externally on pipelines or vessels and measures density through the vessel wall.
This non-invasive measurement principle makes the sensor especially suitable for processes where:
The medium is corrosive, abrasive or hazardous
Process conditions are extreme
Installation of inline sensors is difficult
Process interruption must be avoided
Typical applications include:
Chemical processing
Oil and gas production
Mining and mineral processing
Pulp and paper industry
Waste treatment
Food and beverage processing
Radiometric Measurement Principle
MINITRAC 31 uses the principle of gamma ray attenuation for density measurement.
A radioactive source, typically using Cesium-137 or Cobalt-60, emits focused gamma radiation through the process vessel or pipeline. The sensor on the opposite side detects the radiation intensity after it passes through the medium.
Because gamma radiation is absorbed by the material depending on its density, the sensor can calculate the density value based on the received radiation signal.
Advantages of this measurement principle include:
No contact with the process medium
No moving parts inside the process
Measurement independent of flow conditions
Suitable for high-pressure and high-temperature processes
Ideal for Retrofitting Existing Plants
One of the major advantages of MINITRAC 31 is its ability to be installed without modifying existing process equipment.
Since the sensor is mounted externally, users can add density measurement points without:
Cutting pipelines
Installing process connections
Stopping production for major modifications
The compact housing design also allows installation in locations with limited space or difficult accessibility.
Reliable Density Measurement Without Process Contact
MINITRAC 31 has no wetted parts, meaning the sensor does not directly contact the measured medium.
This provides several benefits:
No corrosion damage to sensor components
No contamination of the process
Reduced maintenance requirements
Longer service life compared with contact-based measurement devices
The non-contact design helps maintain high plant availability, especially in critical industrial processes.
Compact Design for Flexible Installation
The MINITRAC 31 features a compact construction that allows flexible mounting on various types of equipment.
It can be installed on:
Pipelines
Storage vessels
Reactors
Process tanks
Special-shaped vessels
The sensor is suitable for applications where conventional density meters cannot be installed due to space limitations or difficult process conditions.
High Accuracy and Stable Measurement Performance
The MINITRAC 31 provides reliable density measurement with an accuracy of approximately 0.1%, helping operators maintain stable process control.
The measurement is largely unaffected by:
Pressure changes
Temperature variations
Flow conditions
Mechanical vibrations
This makes it suitable for continuous monitoring in industrial production processes where consistent density information is required.
Flexible Communication and Integration
MINITRAC 31 supports common industrial communication interfaces for easy integration into automation systems.
Available communication options include:
4…20 mA/HART
PROFIBUS PA
FOUNDATION Fieldbus
The sensor can also be configured and adjusted using VEGA display modules, PC-based tools and standard HART communication equipment.
Suitable for Safety-Critical Applications
For applications requiring additional functional safety, MINITRAC 31 supports SIL2 qualification.
The sensor also offers various international approvals for hazardous areas, including:
These certifications allow the device to be used in demanding industrial environments where explosion protection is required.
Typical Applications
Chemical Industry
MINITRAC 31 is used for density monitoring in chemical processes where direct contact measurement may cause corrosion or maintenance issues.
Applications:
Chemical concentration monitoring
Reactor process control
Slurry density measurement
Oil and Gas Industry
The sensor supports density measurement in pipelines and process equipment.
Applications:
Hydrocarbon processing
Separator monitoring
Process optimization
Mining and Mineral Processing
For slurry and bulk material applications, MINITRAC 31 provides reliable density information without affecting material flow.
Applications:
Mineral slurry measurement
Thickener monitoring
Concentration control
Pulp and Paper Industry
The sensor can measure density in challenging process fluids.
Applications:
Pulp consistency monitoring
Slurry measurement
Process control
Food and Beverage Industry
Non-contact measurement helps maintain hygienic process conditions.
Applications:
Concentration measurement
Product quality monitoring
Process optimization
