On this page you can read about the other applications.


Measuring real-time COD is becoming increasingly important as we strive to take better care of the environment. In-line COD measurement will help you to trace leaks in the factory and to determine their possible causes. This can save money during the production process as well as in the WWTP (less consumption of oxygen and therefore less sludge). The Rhosonics Model 9585COD Meter can be used to measure the COD value of brewery wastewater streams.

COD is normally measured in the laboratory through chemical reactions with oxygen. Rhosonics offers a different way to measure the amount of COD in real time: CODeq (equivalant results, but using improved technology). Rhosonics uses a combination of multiple ultrasonic technologies in a single sensor, in combination with a conductivity sensor, to determine CODeq and TSSeq: the model 9585. The factory-programmed calibration is an advanced regression model, based on the ultrasonic properties of a variety of the most common organic materials, such as alcohols, sugars, and so on.

The Rhosonics Model 9585 employs a hybrid ultrasonic sensor that measures a number of ultrasonic properties of water. In conjunction with the electrical conductivity, an ultrasonic equivalent value can be reached to determine the COD value of the water.


FGD (Flue Gas Desulfurization) is a technology used for removing sulphur from the exhaust flue gasses emitted in coal- and oil-burning power plants. In order to optimize the desulfurization process, it is important to measure the density of the process slurry (lime stone) in real time, so that efficiency can be improved and waste reduced.

These measurements are often done using nuclear technologies. However, to avoid complex government regulations with regards to the handling of nuclear isotopes, contact-less Rhosonics density sensors offer a reliable and comparatively cheaper solution. Furthermore, with our sensors you will avoid a lot of difficulties encountered with other types of sensors that can lead to possible damages due to complex flow paths, which may lead to either blockages or erosion.

Have a look at the SDM Slurry Density Meter. This model is regularly used for this specific application. Rhosonics instruments monitor the attenuation with ultrasonic signals, of which the density can be measured directly and in-line.


Sulphuric acid is an important raw material in the chemical industry, used in many different processes. Oleum is produced by dissolving SO3 in H2SO4. Sulphuric acid is produced by dissolving water in oleum (also called double contact process). The most important thing with sulphuric acid is that it becomes oleum above 100%. This makes it a very interesting liquid. In order to monitor the dilution process, an accurate and reliable real-time in-line analyser is needed. Rhosonics has developed a very accurate analyser for this purpose, namely model 8500. This ultrasonic analyser is able to determine concentrations in different possible ranges, based on the velocity of sound and through measurement of the liquid’s temperature. The concentration of aqueous solutions of sulphuric acid or oleum is reported as %w/w H2SO4.


KOH is produced by electrolysis of potassium chloride, or by boiling a solution of potassium carbonate (potash) with calcium hydroxide (slaked lime). The process leads to a metathesis reaction that results in calcium carbonate. When it precipitates, it leaves potassium hydroxide in solution. KOH forms a strong alkaline solution when dissolved in water or alcohol. It has almost the same properties as NaOH.

Potassium hydroxide (also called caustic potash, potash lye, or potassium hydrate) is a caustic metallic base with high conductivity range. KOH is used in many industries, including companies specialized in the refinement of petroleum and natural gas. Within these industries, it is used to remove organic acids and sulphur compounds. It is also used in the production of biodiesel and soft soaps.

Rhosonics has developed very accurate analysers for this application: Model 8500and Model 9680. Both ultrasonic analysers measure the velocity of sound with a high degree of accuracy, in line and in real time. By measuring the speed of sound, the actual concentration can be determined in a wide concentration and temperature range. Model 9680 has additional features: it can also measure the density and amount of solids.


NaOH, sodium hydroxide or caustic soda is a chemical that is used in many industries and in different processes. Accurate measurement of NaOH online and in real time is important. There are many different systems on the market, but most of them have one or more disadvantages. Some, for example, are sensitive to pollution or difficult to calibrate; others may incur high maintenance costs.

Rhosonics ultrasonic technologies, such as the model 8500 series, can measure sodium hydroxide concentration from zero up to the saturation point in different ranges. Rhosonics analysers measure physical parameters using ultrasonic signals. The analyser determines the actual concentration of the sodium hydroxide solution through measuring the velocity of sound through the medium. The system is less sensitive to pollution than refractometer technology. It also eliminates high operating costs and the need for frequent, complex maintenance.

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