A concentration meter determines how much of a solute is present and expresses a reading for the operator. People may use such equipment for a single reading of a solution under evaluation or it can be installed to take continuous measurements as part of an ongoing process. Accurate concentration data is needed for activities like bench research in a lab, quality control for manufacturing, and testing of components used in food production. Products like wine, for example, are assessed to find out how much sugar they contain, a measurement termed "brix," which plays an important role in how the wine is processed.
Systems to measure concentration can work in several ways, depending on what kind of data they are supposed to record. Samples may be passed through a concentration meter, or it could be lowered into a solution to take a density measurement. Some use tools like light refraction, while others may pass an electrical current through the solution to measure density, which provides information about concentration.
A variety of of measurements can be used; technicians typically choose a mode appropriate to the product they are measuring, based on industry standards and conventions. The device may allow people to switch modes depending on what they are measuring and where they are. Calibration is also important to make sure the concentration meter is working properly. A technician can calibrate the device by taking a solution of known concentration and testing it to see if the machine reads it correctly.
In manufacturing, a concentration meter can be an important tool. Products like fertilizers, pharmaceuticals, and battery acid need to be made to very precise specifications so they will perform as expected while meeting quality standards. Periodic testing or continuous monitoring are required to keep an eye on the production process and ensure that any problems are caught as early as possible. For example, if the concentration of a solution used to make a medication is not strong enough, the drug wouldn’t have a standard potency and might not work as well.
Beer and wine production both require the use of a concentration meter. Other products may require testing; in candy manufacturing, for example, companies make syrups with sugar and want to be able to test them to confirm the solution is of an appropriate concentration to move on to the next step. Manufacturers may make specialty equipment for these applications, including devices that can be sterilized between batches to prevent contamination.