In the world of level measurement technology, two heavyweights go head-to-head: Radar Level Transmitters and Ultrasonic Level Transmitters. These devices play a critical role in industries ranging from wastewater treatment to petrochemicals, ensuring precise measurement of fluid levels in tanks and vessels. But what sets them apart, and how do you determine which one is the right fit for your application? In this article, we’re about to embark on a journey into the realm of level measurement technology, uncovering the real differences between Radar and Ultrasonic Level Transmitters. Understanding these distinctions will empower you to make informed choices for your level measurement needs. Let’s dive in and explore the fascinating world of these two indispensable devices.
What is a Radar Level Transmitter?
A radar level transmitter, popularly known as a guided wave radar level transmitter (GWR), is a contact-based level measurement method that follows the principle of time domain reflection (TDR). They use a probe that guides high-frequency electromagnetic waves as they travel from a transmitter to the media being measured. Low-energy electromagnetic waves are transmitted along with the probe as it traverses the process media, and their partial energy is reflected in the sensor circuitry using the TDR measurement technique. The fluid level is estimated by taking the time differential between the sent and received pulses into account. Unlike other level measuring techniques, a guided wave radar level transmitter measures readings independent of the physical or chemical properties of process media. These transmitters perform admirably in both solids and liquids.
Advantages of Radar Level Transmitter
- Radar level transmitters can measure the levels of liquids, solids, slurries, or interfaces.
- Since there is no moving part, maintenance is much less.
- There are no effects on measurement due to liquid turbulence, density change, temperature change, or pressure change.
- Non-contact type radar level transmitters are also most suitable for highly corrosive fluids.
Limitations of Radar Level Transmitter
- Readings will fluctuate if the dielectric constant of the material changes.
- In using contact-type radar, if any material sticks on the probe, it will form echoes, and we will get the wrong reading. We need to pull the probe out clean it, and reinstall it again.
- In non-contact type radar, if any material sticks on the antenna, then we need to clean it.
- The minimum dielectric constant difference for interference measurement should be 5. Otherwise, we won’t be able to measure interface echo properly.
Applications of Radar Level Transmitter
- Mining Industry
- Captive Power Plant
- Paper and pulp industry
- Aeronautics industry
- Cement Plants
- Steel Plants
What is Ultrasonic Level Transmitter?
Non-contact level measurement is used by ultrasonic level transmitters. To generate mechanical waves, the transmitter employs a piezoelectric transducer. They work by transmitting a sound wave to the process media being measured. The signal from the process media to the transducer is required for accurate level measurement. Heavy vapors, surface turbulence, dust, tank blockages, and other conditions can all have an impact on the returning signals. As a result, while utilizing ultrasonic level measurement, it is critical to consider sound properties.
Advantages of Ultrasonic Level Transmitter
- An ultrasonic-level transmitter may detect levels without making physical contact with the medium.
- It has a vast size of up to 6 meters.
- This type of transmitter can detect a wide range of substances, including liquid levels, solid levels, foam levels, and many more.
- As there is no moving part in an ultrasonic-level transmitter, they are almost maintenance-free.
- Ultrasonic level transmitters are simple to set up. Only a few factors, such as tank height, blocking distance, and damping, are required for this transmitter to function properly.
- Ultrasonic level transmitters are less expensive than other non-contact type level transmitters, such as radar type level transmitters.
Disadvantages of Ultrasonic Level Transmitter
- In vacuum servicing, we cannot use an ultrasonic level transmitter. This is due to the fact that ultrasonic waves are mechanical waves that require a medium to travel.
- The ultrasonic transmitter is incompatible with media that absorb ultrasonic frequencies.
- A change in temperature causes a change in the speed of the ultrasonic waves. As a result, the height gained will likewise fluctuate. So, temperature compensation is a must.
- The ultrasonic level transmitter is not suitable for use in high-temperature environments. Because the sensor is made up of a kind of polymer only.
- Sometimes, moisture droplets get attached to the sensor tip. Because of this, the ultrasonic level transmitter starts showing 100% level. As a result, removing the ultrasonic level transmitter and cleaning the ultrasonic level transmitter is required.
Applications of Ultrasonic Level Transmitter
- Food & Beverage industry
- Chemical industry
- Tank water level measurement
- Open tank level measurement
Radar Level Transmitter vs. Ultrasonic Level Transmitters
In terms of Environmental Conditions:
Ultrasonic transmitters should be installed in a controlled setting. This is due to the possibility of dust, humidity, and other physical characteristics contaminating and affecting the precision of the reflected signal. Radar transmitters, on the other hand, perform effectively even in a dusty and generally tough industrial environment.
In terms of Pressure Limits:
High or negative pressure restrictions are not suitable for ultrasonic transmitters. The device can withstand up to 3 bar of operational pressure. However, radar may work at maximum operating pressure over 4 Mpa.
In terms of Temperature Limits:
Temperatures above 80°C are suitable for ultrasonic transmitters. Incorrect measurements may result from varying process temperatures or variations. Guided wave radar level transmitter works well in temperatures up to 315°C.
In terms of Accuracy:
Changes in density, acidity, and viscosity have little effect on radar-level transmitter accuracy. Radar transmitters are, therefore, more precise than ultrasonic transmitters. High-accuracy radar transmitters are used to measure storage tank levels.
In terms of Performance:
The ultrasonic transmitter’s performance is determined by the strength of the reflected sound wave, whereas radar functions well regardless of the process circumstances.
In terms of Applications:
Ultrasonic transmitters are an excellent choice for solid and liquid level measurement. They are commonly used for item profiling and presence detection. The car wash industry is an excellent illustration of how ultrasonic sensors may be used to increase efficiencies and improve procedures. The most common applications of radar transmitters are minerals and mining, oil and gas, asphalt blending tanks, alum and wax tanks, pharmaceuticals, pulp and paper, and more.