Level Measurement
What is level measurement?
Level measurement is the process of measuring the level of a liquid or solid material inside a tank, silo, container or reservoir. Measurement is calculated from the distance between the liquid or solid material surface and a predetermined reference point.
Level measurement is typically expressed in feet or meters and can also be given as a percentage (i.e. 75% full). Level measurement can also be used to determine volume or mass inside a tank.
Why is it important?
Accurate and reliable level measurement is essential for many process applications. Monitoring and controlling the level of liquids or solid materials in tanks is critical for manufacturing process control and automation, inventory management, maintaining safety, ensuring efficient operations, optimizing production and much more.
Inventory Management
Inventory is critical for continuous production, and level measurement plays an important role in control and management by monitoring the level of liquid or solid material in storage tanks, silos or containers. Monitoring inventory levels enables manufacturing plants to plan production, optimize ordering, avoid shortages or excess inventory, and minimize downtime.
Process control and optimization
To maintain optimal process conditions monitoring the level of liquids or solid materials in a tank and relaying the information for control and optimization is critical. Precise control ensures continuous production – no downtime, prevents overflows or shortages, and improves product quality and operational efficiency.
Quality control
For manufacturing processes with mixing, blending or reactions, measuring level is critical to help control ingredient ratio, concentration or dosage. Level sensors are also used for filling conditions and monitoring the shape or profile of finished products on conveyor systems for product consistency and quality standards.
Safety
Level measurement helps ensure the safety of workers, process equipment and the environment. Overfilling or underfilling tanks can lead to unfavourable outcomes, including hazardous spills, equipment damage, and accidents. Monitoring provides an early warning of high or low tank levels and enables operators to act quickly to minimize risk.
What industries use level measurement?
Level measurement is used extensively across many industries for a variety of applications.
- Water and wastewater
- Plastics
- Chemical
- Oil and gas
- Mining
- Cement
- Food and Beverage
- Pharmaceutical
- Environmental
- Agricultural
- Marine
- Construction
Types of Level Measurement
Continuous Level Measurement
Continuous level measurement provides real-time information on liquid or solid material levels in a tank throughout the entire span. It is commonly used for automation (i.e. pump control) and integration with control systems, and enables process optimization and improved efficiency.
Point Level Measurement
Point level measurement indicates whether the liquid or solid material has reached a certain level in a tank. It is commonly used for process control and triggering alarms.
Methods & Technologies
Many technologies are available for measuring level, from simple to more advanced methods. Manual or mechanical methods such as floats, sight glasses, tape level or dip probes are simple, low-cost solutions without automation. In many cases, maintenance and manpower requirements are high. Advanced methods such as radar, ultrasonic, capacitance or laser technologies provide higher performance and automation capabilities for process control and require less manpower.
At ABM, we specialize in ultrasonic and radar level technologies so we’ll touch on those two here:
Radar sensors use electromagnetic waves for measurement focused by an antenna. The sensor emits electromagnetic pulses toward a target. The pulses reflect off the target and are received by the same antenna. Using the time-of-flight principle, the sensor calculates the distance between the sensor and the target. Radar is ideal for challenging environments such as those with vapours, gases, temperature variations, extreme temperatures, extreme dust, wind, foam, ice or acoustic noise.
For ultrasonic measurement, the sensor transmits a pressure wave from a transducer that travels at the speed of sound to a target. The wave is reflected off the target and returns to the transmitter. The sensor receives the echo and calculates the distance between the sensor and the target using the time-of-flight principle. Ultrasonic is the ideal solution for liquids and solids without gases / vapours such as CO2, CO, H2S, H2.
Instrument Selection
When it comes to measuring level, there is no one size fits all solution. Selecting the right level sensor for your application depends on material type and properties, tank design, environment conditions (i.e. temperature, pressure, moisture, dust, and vapour), accuracy requirements, maintenance requirements, and budget. Working with a knowledgeable professional can offer guidance in selecting the right solution for your application.
For help with your level monitoring application, contact us at +1 (705) 740-2010 or email info@abmsensor.com.