RADAR LEVEL MEASUREMENT Each device has a particular target area of application
Process instrumentation solutions supplier Krohne has added six new 24 GHz and 80 GHz transmitters to its Optiwave series of frequency-modulated continuous-wave (FMCW) radar level transmitters, which are aimed at liquid and solid applications in a range of industries.
Based on over 28 years of experience with FMCW technology, the company notes that each device has a particular target area of application, for example, agitated and corrosive liquids, narrow tanks with internal obstructions, or powders and dusty atmospheres.
All new Optiwave devices feature two-wire 20 mA Hart 7 communication and come with an extensive choice of process connections, starting from ¾''. The devices feature a large backlit liquid-crystal display with a four-button keypad, a quick setup assistant for easy commissioning and come with free PACTware device-type manager with full functionality.
“While approvals for hazardous areas are already available, other approvals, including the safety integrity level (SIL), are ongoing,” the company notes.
New Devices for Liquids
The Optiwave 3500 is an 80 GHz FMCW radar aimed at hygienic applications in the food, beverage and pharmaceuticals markets. It has a range of hygienic connections and can measure right up to the process connection.
“Thanks to its narrow beam angle and small dead zone, it is capable of measuring in small and narrow tanks, even with agitators,” the company enthuses.
Optiwave 5400 is a 24 GHz FMCW radar for liquids in basic process applications in the chemicals, oil and gas and power industries.
“It provides accurate readings in closed tanks, in open air applications such as rivers or dams, and even in processes with fast-changing levels,” the company notes.
The Optiwave 7 400 is a 24 GHz FMCW radar designed for liquids in harsh environments such as tanks with agitators containing corrosives up to +700 ºC / +1 292 ºF (such as molten salt in solar plants).
The Optiwave 7400 is also suitable for the chemicals, petrochemicals, power and oil and gas industries and comes with a large choice of antenna options, such as the drop antenna, as well as heating, cooling or purging systems for metallic horn antennas.
For applications with corrosive or dangerous liquids, the company notes that a flange plate protection or a metaglas – which is a trademark of safe sight glass manufacturer Herberts Industrieglas – second sealing barrier is available.
“The quick coupling system permits the removal of the converter under process conditions.”
The Optiwave 7500 is an 80 GHz FMCW radar, which covers the same industries as Optiwave 7400 and up to +150 °C / +302 °F, 40 barg / 580 psig.
The company enthuses that the Optiwave 7500, with its small beam angle and negligible dead zone, is suitable for liquid applications in small and narrow tanks with internal obstructions like agitators or heating coils, as well as tanks with long nozzles.
“This 80 GHz radar can even measure through tank roofs made of non-conductive material. It features a flush-mounted Peek Lens antenna and measures the level of a product from the antenna down to the tank bottom over a distance of 100 m.
New Devices for Solids
The Optiwave 6400 is a 24 GHz FMCW radar for solids, from granulates to rocks in industries such as minerals and mining, chemicals, agriculture, or power generation.
It measures the level of solids such as stone, plastic granulates or coffee beans accurately and reliably, the company explains.
“The proven drop antenna minimises scaling and is unaffected by the angle of repose, thus eliminating the need for expensive antenna aiming kits or purging systems.”
The Optiwave 6500 is an 80 GHz FMCW radar for powders and dusty atmospheres, suitable for the same industries as Optiwave 6400.
It features specific algorithms and high signal dynamics to provide reliable and accurate readings, despite the challenges linked to fine powders such as dust, low-reflective media, build-up and uneven surfaces.
“Owing to the small beam angle of the flush-mounted lens antenna, it is best suited for high and narrow silos even in the presence of internal obstructions,” the company notes.
The new 24 GHz and 80 GHz transmitters complement the two existing 6 GHz and 10 GHz devices of the Optiwave series: Optiwave 1010 is a 6 GHz FMCW radar suited for clean liquids in bypass chambers and Magnetic Level Indicators (MLI).
The company explains that it is welded to the bypass chamber or MLI and measures the position of the float or the liquid level.
The Optiwave 5200 is a 10 GHz FMCW radar for liquids in storage and simple process applications with a range of options, SIL two approval and a choice of fieldbus communication options.