Concentration measurement in acids
The concentration measurement in acids is an essential part of many chemical and industrial processes. It determines the concentration of an acid in a solution, which is crucial for understanding its chemical properties and reactions.
The most common acids used in chemistry include: Hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃), acetic acid (CH₃COOH) etc.
Concentration measurements with LiquiSonic® Measuring devices
The LiquiSonic® Measuring systems enable inline concentration measurements of acids. The measurement technology is capable of analyzing the components of mixtures and can provide information about concentration or density in real-time. The sensors are based on the principle of ultrasonic speed measurement. Therefore, they are almost maintenance-free and can reliably provide measurement values even under demanding conditions.
Measurement methods of LiquiSonic® for determining the concentration of acids
Our LiquiSonic® Measuring systems are based on the principle of sound velocity measurement and are used in various applications to measure the concentration of different acids.
To determine the sound velocity, a sound pulse is sent through the liquid and the time is measured until the pulse reaches the receiver. Since the distance between the ultrasonic transmitter and receiver is constant by design, the sound velocity can be calculated.
Installation of LiquiSonic® Measurement systems
The LiquiSonic® Sensors can be installed directly into the user's system, for example in pipelines, without a bypass. There are also various versions tailored to specific applications and equipped with special properties.
What is an acid?
Acids are chemical compounds that can release hydrogen ions (H+) in aqueous solution. The acidity is measured in pH, which has a scale from 0 to 14. At a pH of 7, the solution is neutral and contains equal amounts of H+ ions and OH- ions. Values below 7 indicate acidic character, while values above 7 indicate basic character.
Most acids are soluble in water and can be corrosive or caustic depending on the concentration. An example of an acid is hydrochloric acid, which is widely used in industry and laboratories. It is important to be aware of the properties and effects of acids to handle these substances safely and effectively.
Which liquids can be measured?
As important components in numerous production processes, acids must be regularly tested to ensure their efficiency and quality. Various methods can be used to test or improve specific properties.
One of the most commonly used acids is Hydrochloric acid (HCl), which is used for cleaning pipes and tanks. Sulfuric acid (H2SO4), a strong acid, is often used to lower pH values or as a cleaning agent for stainless steel. Other common acids are Nitric acid (HNO3), Phosphoric acid (H3PO4) and Hydrofluoric acid (HF), each having its specific applications. The choice of the right acid for the testing process depends on the type of liquid and the goals of the test. The correct application of acids helps to increase the efficiency and quality of process liquids and ultimately improve the quality of the final product.

How is the concentration of an acid determined?
The concentration of acids can be determined in various ways. Some common methods are:
- Sound velocity measurement: This method is based on measuring the speed at which sound waves travel through an acid solution. It is particularly suitable for acids with different molecule sizes and structures, as the sound velocity is influenced by these factors.
- Titration: In titration, the acid to be tested is mixed with a base of known concentration until a neutralization point is reached. This method is ideal for precise measurements but unsuitable for acids that do not fully react with the base or where side reactions occur.
- pH measurement: This method measures the hydrogen ion concentration in the solution to determine the acid strength. It is effective in aqueous solutions but unreliable for very strong acids or in the presence of other ions that can affect the pH meter.
- Conductivity measurement: Here, the electrical conductivity of the acid solution is measured, which depends on the ion concentration. This method is useful for ionic acids but inaccurate for non-ionic or weak acids, as their ions do not sufficiently contribute to conductivity.
- Spectroscopy: Spectroscopic methods, such as UV-Vis spectroscopy, measure the absorption or emission of light in an acid solution. This is suitable for acids that absorb specific wavelengths, but not suitable for acids without characteristic absorption bands.
- Density measurement: The density of an acid solution can provide information about its concentration. This is particularly effective for pure acids or solutions with a known solvent, but problematic for mixed solutions or when the density is influenced by other dissolved substances.
A classical method is titration, where a base with known concentration is added to the sample until a neutralization point is reached. This method is often used in the laboratory to determine the exact molarity of an acid. The advantages of titration are its high precision and reliability, while the disadvantages include the need for skilled operators and time-consuming execution.
Another common method is pH-metry, where the pH value of a solution is measured with a pH meter. This method is often used in industrial processes to monitor the acid concentration in real time. Advantages of pH-metry include quick and easy handling and the possibility of continuous measurement. A disadvantage can be the need for regular calibration and maintenance of the pH meter.
Finally, there are spectroscopic methods such as UV/VIS spectroscopy, which are based on the absorption of light of specific wavelengths by acid molecules. This method is used in research and development to determine the concentration of acids in complex mixtures. Spectroscopic methods are advantageous for their ability to detect very low concentrations, but they are significantly more demanding in terms of required equipment and expertise.
Applications of acid concentration measurements
In the chemical industry, acid concentration measurements play a crucial role in a variety of fields and applications. These measurements are of great importance for quality assurance and process control in various sectors such as fertilizer production, the petrochemical industry, the pharmaceutical industry, the food industry, water treatment and environmental protection, battery manufacturing, as well as metallurgy and ore processing.
Acid concentration measurements make it possible to monitor the progress of chemical reactions, ensure product quality, and ensure that the manufactured products meet the required specifications. In the production of fertilizers, for example, accurate measurement of acid concentration is crucial to ensure that the right nutrients are present in the right amounts. In the petrochemical industry, such measurements help tomonitor and ensure product purity.
In the pharmaceutical industry, concentration measurements of acids are indispensable. They make it possible to verify the effectiveness of medications and ensure that the correct dosage is administered. In the food industry, such measurements help with quality assurance and control of the acid content in various products. In water treatment and environmental protection, concentration measurements of acids are important to monitor pollution and ensure water quality.
In battery manufacturing as well as metallurgy and ore processing, concentration measurements of acids are used to monitor the composition of materials and optimize process efficiency.
Overall, concentration measurements of acids are fundamentally important to ensure product quality, process efficiency, and environmental safety in a variety of applications and industries.
Where is the concentration measurement of acids carried out?
In various manufacturing processes, the concentration measurement of acids plays an important role. Pipelines, in particular, represent a critical point, as a too high concentration of acids can damage the pipes and lead to leaks. Furthermore, unwanted chemical reactions can be triggered, affecting both the quality of the final product and the safety of employees.
For this reason, regular monitoring of acid concentration through precise real-time measurements is indispensable. Various measurement methods, such as pH measurement or ion-selective measurement (ISE), are used. Concentration measurement is carried out not only in pipelines but also at other critical points in the process, such as in tanks or reactors.