Applications

Dissolved oxygen (DO), incorporated into juices during processing, affects quality parameters of the beverage during storage such as Vitamin C concentration, color, and aroma. Various oxygen removal methods are used during juice production, such as vacuum-deaeration or gas sparging to increase product quality and extend shelf life. However, these methods have the drawback that the aroma might be affected since the volatile compounds are also removed. By assessing the DO content in fruit juices, manufacturers can improve the overall product quality. This application note describes a fast and accurate determination of dissolved oxygen in juices by using an optical sensor.

Oxygen diffuses into water sources from the air via aeration, however several factors can reduce the dissolved oxygen (DO) content in water. First, as water warms up, oxygen is released into the atmosphere. Secondly, oxygen is consumed by bacteria and other microorganisms which feed on organic material. Finally, plants can also consume oxygen in certain situations.Human-induced alterations can have a negative influence on surface water when DO values fall below crucial limits for maintaining the life supporting capacity of freshwater ecosystems. Therefore, monitoring the DO content in surface water by an optical sensor to assess its quality is important.

Dissolved oxygen (DO) is generally considered detrimental to wine quality, especially if introduced after fermentation, storage, or bottling. The presence of oxygen after primary fermentation and during the later stages of winemaking can enhance browning reactions, chemical and microbiological instability, and the formation of off-flavors such as acetaldehyde. Knowing the DO content in wine is important through the entire wine production process, because oxidation is a common fault in bottled wines. With the 913 pH/DO meter and the 914 pH/DO/Conductometer, the oxygen content of wine can be determined quickly and easily directly on site.

Dans les approvisionnements en eau des municipalités, une teneur élevée en oxygène dissous (OD) est souhaitable car elle améliore le goût de l'eau potable. Cependant, les niveaux élevés d'OD accélèrent également la corrosion dans les conduites d'eau. C'est pourquoi les industries utilisent de l'eau contenant le moins d'oxygène possible et ajoutent des épurateurs tels que le sulfite de sodium pour éliminer tout oxygène de l'approvisionnement en eau. Les conduites d'eau municipales sont normalement recouvertes à l'intérieur de polyphosphates pour protéger le métal du contact avec l'oxygène, ce qui permet des teneurs en OD plus élevées. Par conséquent, il est important de surveiller en ligne la teneur en OD d'un approvisionnement en eau afin d'évaluer sa teneur en OD pour améliorer le goût ou minimiser la corrosion des tuyaux. L'utilisation d'un capteur optique, tel que l'O-Lumitrode, permet une détermination rapide et fiable conformément à la norme ISO 17289.

Acrylic dispersion paints are made of pigment suspended in acrylic polymer emulsions, which also include other organic material such as plasticizers, defoamers, or stabilizers. Acrylic dispersion paints are water-soluble but become resistant to water when dry. Due to the fact that once dry, acrylic dispersion paints can no longer be used, they should be stored air-tight at room temperature. For research purposes, it is of interest to assess the dissolved oxygen (DO) concentration in such samples as it is assumed that the DO amount can be related to the storage life. This Application Note describes a fast and accurate determination of dissolved oxygen by using an optical sensor.

In the food industry, it is essential to determine and monitor certain quality parameters to guarantee consistency. This is especially important for liquid dairy products, which are subject to a strict cold chain. Both the dissolved oxygen (DO) and the pH value have proven to be reliable quality criteria. Oxygen shortens the shelf life and influences the product quality (e.g., nutritional value, color, and flavor). The DO content depends on the salinity in the sample, which is automatically calculated and corrected by the 914 pH/DO/Conductometer during the parallel conductivity measurement. Acidity is another important characteristic to measure that can be checked easily using the pH value. With the 914 pH/DO/Conductometer, all important quality criteria can be monitored with one device.

Le traitement de l'eau à l'ozone (O3) est une procédure courante de désinfection des piscines. Il est important qu'une quantité suffisante mais non excessive d'O3 soit produite pour désinfecter l'eau. L'ozone est également utilisé dans le traitement des eaux potables et usées, car il est nettement plus efficace que le chlore pour inactiver ou tuer les virus et les bactéries. Cette note d'application décrit une méthode permettant de déterminer la concentration d'ozone dans l'eau par titrage potentiométrique conformément à la norme DIN 38408-3.

L'« oxygène dissous » désigne la quantité de molécules d'oxygène (O2) dissoutes dans une phase liquide dans certaines conditions. Dans ce livre blanc, deux méthodes différentes d'analyse de l'oxygène dissous, le titrage et la mesure directe, sont comparées et opposées pour aider les analystes à déterminer la méthode qui convient le mieux à leurs applications spécifiques. Nous nous concentrons ici principalement sur la détermination de l'O2 dissous dans l'eau. Toutefois, le même principe s'applique à d'autres phases liquides, comme les boissons alcoolisées ou non.