Point Level Measurement: Challenges in the Weighing and Mixing Section
During the weighing and mixing of components, numerous requirements and specific conditions must be considered for level and point level measurement. Sensors must operate reliably and without interference, even under challenging conditions such as dust, temperature fluctuations, or varying material properties.
As the processes often involve extreme temperatures, such as those caused by bitumen or hot aggregates, high temperature resistance is just as crucial as mechanical durability to withstand vibrations and other impacts. Additionally, the sensors must be wear-resistant against abrasive materials and chemically resistant to substances such as bitumen.
A compact design facilitates integration into existing systems, especially in confined installation spaces. At the same time, low-maintenance operation minimises downtime and enhances process reliability.
Safety aspects, such as effective overfill protection and compliance with explosion protection regulations, including Ex certifications, are essential. For efficient process control, real-time monitoring of measurement data is also crucial, particularly when handling heterogeneous materials with fluctuating flow properties.
These requirements play a key role in ensuring efficiency and safety throughout the entire production process.
RFnivo® – Precise Point Level Measurement in the Weighing and Mixing Process
The capacitive point level sensor RFnivo® provides a robust and flexible solution for demanding applications such as weighing and mixing processes in asphalt production. Its compact design, high durability, and ease of use make it the ideal choice.
Advantages in Application
- Space-saving and precise: The RFnivo® can be installed close to the container wall, making it ideal for confined installation spaces. The measurement remains accurate and reliable, unaffected by the influence of the container wall.
- Robust and durable: The measurement principle is designed to remain unaffected by flowing material. High-quality materials ensure a long service life, even in dusty, high-temperature, or high-flow conditions.
- Low maintenance: With automatic calibration, the sensor is easy to install and commission. It remains stable without the need for frequent adjustments, regardless of the properties of the measured material.
Technical Features
- Active Shield Technology: This system prevents interference from adhering material, ensuring low-maintenance operation.
- High durability: Depending on the model, RFnivo® sensors can operate at process temperatures of up to +500°C/+932 °F and pressures of up to 35 bar/507 psi.
- Versatility: With a sensitivity starting from a DK value of 1.5, RFnivo® is a true all-rounder for various bulk solids and liquids.
- Flexible designs: Variants such as rod or cable versions, as well as remote housing options, provide solutions for diverse installation conditions.
- Ex-proof certifications: International approvals for gas and dust explosion hazard areas expand its application range.
Precise Dosing for Optimal Asphalt Quality
The specific properties of asphalt components – from bridging and the tendency of rock dust to clump to the varying flowability of bitumen – present unique challenges. Depending on the requirements of the intended application, the composition of the asphalt mix varies, making precise dosing of materials with mineral or bitumen scales essential to achieving the desired result.
The RFnivo® ensures a consistent material supply, guaranteeing that each component is added in the exact required quantity. This forms the foundation for a high-quality and reliable asphalt mixture.
The RFnivo® Series – Versatile and Reliable Point Level Sensing
RF Technology: Precision Through High Frequency
The name RFnivo® incorporates Radio Frequency – the technological foundation of the capacitive measurement principle. High-frequency signals are used to detect changes in capacitance, enabling precise and reliable level detection in containers, whether for bulk solids, liquids, or even interface layers in liquid processes.
The capacitive level switch automatically calibrates to the reference capacitance of an empty container. When the probe is covered by the medium, the change in the dielectric constant results in a measurable capacitance shift, triggering a switching signal. For liquids, frequency changes caused by the capacitance variation are also evaluated.
Thanks to the integrated Active Shield technology, functionality remains unaffected even with sticky, highly viscous, or challenging media.
Universal Designs for Versatile Use Across Various Industries
The RFnivo® series offers a wide range of capacitive sensors for both bulk solids and liquids. The liquid sensors are also suitable for applications involving pastes, foams, and sludges.
With a choice of designs, including rod and cable versions, variants with inactive extensions, or remote housing options, RFnivo® RF sensors are highly versatile. They are used in process vessels, silos, tanks, hoppers, pipelines, and chutes. The Inverse Frequency Shift technology ensures highly precise measurement results, regardless of the medium’s properties.
With encapsulated digital electronics, an integrated display, and a freely programmable user menu, the RF 8000 series offers enhanced convenience and flexibility. International certifications for gas and dust explosion hazard areas further expand its application range, making it the ideal solution for a wide variety of industries.
With overfill protection and dry run prevention, RFnivo® sensors contribute to long-term process safety, ensuring reliable and precise monitoring – even under the most demanding conditions.
Expert Solutions for Demanding Applications
Thanks to UWT’s extensive expertise and years of industry experience, customised measurement and monitoring solutions can be developed even for complex processes, such as those in the asphalt industry. Each solution is precisely tailored to meet the specific requirements of every application.
For more information and detailed solutions in the building materials and cement industry, the new UWT industry brochure is now available for download.
Download now and learn more!
