A matter of frequency
The benefits of high-transmission radar in level measurement applications
The development of 80 GHz radar sensors signals a brave new world for liquid level measurement, one where radar can go where it has never gone before. This is truly an exciting era in automation. With high-frequency devices on the rise, now is a good time to examine why radar technology is coming into its own and the benefits of using these new sensors in automated processes.
Advancements create availability
The availability of 80 GHz radar sensors is a function of cost and innovation. Microwave development has advanced to the point that it’s comparatively affordable, and the decreased expense has led to increased use across multiple industries. Just as computer hardware prices dipped low enough to put a PC in every home, it is now possible to put 80 GHz radar in every plant. This was thought impossible a mere 20 years ago.
Yet cost wasn’t the only thing stopping plant operators from using high-frequency radar before now. On their own, high-frequency sensors don’t stand up to harsh process conditions as well as their lower-frequency cousins, which are adept at penetrating foam and performing through condensation and buildup. However, modern radar instruments are engineered to overcome these obstacles with large dynamic range and software algorithms that filter out interference. These innovations have made the affordable technology relevant to real applications. Now that 80 GHz radar is available and practical for liquid level measurement, users should get accustomed to sensors with better focus, versatile size, and enhanced resolution.
This is the alpha benefit of 80 GHz radar; the one that makes the others possible. In every process, signal focus is crucial to accurate level measurement, and these new instruments emit the most focused signals on the market.
Plant operators have struggled with unfocused radar for decades. The wide beam angle of 26 GHz sensors (and 6 GHz sensors before them) made it difficult for radar signals to miss agitators, heating coils and other vessel internals. The reflections from these installations distorted the echo curve and users were forced to make adjustments to monitor the true liquid level. The new high-transmission models have narrower beams that miss vessel installations—it’s as if they aren’t even there. That is welcome news in chemical and food production, where obtrusive internals are the norm and space is at a premium.
Superior focus makes for accurate measurement without adjustment, but it also opens the door for two other major benefits.
Because their focus is amped up, 80 GHz sensors have small antennas. The new VEGAPULS 64, for example, has the world’s smallest antenna and doesn’t require a large horn to focus its beam at the measured material. The instrument’s small size makes a huge impact, particularly as it applies to retrofitting. Plants can now integrate the most advanced radar devices into their process without shelling out thousands for modifications to their vessels. Smaller instruments, however, aren’t just good for old vessels; they can also help manufacturers stay nimble and market-responsive.
There’s a trend in the pharmaceutical and chemical industries toward batch production. Batching allows operators to produce seasonal and low-volume products with less financial investment. Small batches are produced in small vessels, where conventional wisdom says using radar is impossible due to small process connections. Thanks to the compact design of 80 GHz radar sensors, that is no longer true, and operators no longer have to sacrifice accurate measurement in the name of space.
Imagine looking at the picture on a standard definition television next to that of an HD TV. The high definition picture would be clearer, sharper, and more detailed due to enhanced resolution. Users will see a similar difference switching from low-frequency to high-frequency radar sensors.
When the level of liquid in a vessel gets low enough, 26 GHz radar reads the echo from the material and the echo from the tank bottom as one echo. This tells the user the vessel is empty when it isn’t and presents a natural handicap to process efficiency. 80 GHz devices measure liquid down to the last millimeter, giving users accurate data they can use to optimize their processes. Greater resolution is particularly important for shipbuilders, who count on precise level in large ballast tanks.
High-frequency radar sensors are the next big thing in level measurement. They are the proverbial giant leap, a marker in time after which the process industry will never be the same. Their excellent focusing makes them perfect for vessels crowded with internals, their small size makes them ideal for retrofitting and batch production, and their unrivaled resolution allows users to get every last drop of space from their tanks. The future of level measurement is here.