Inline, Online, Atline, and Offline concepts
The terms "inline", "online", "atline" and "offline" refer to different approaches to sampling and analysis in industrial processes, including bulk material processing. Each approach has its own advantages and challenges and is selected depending on the requirements of the specific process.
- Inline: With in-line sampling and analysis, the material is analyzed in real time directly during the production process. Inline devices are integrated directly into the process stream and perform continuous measurements without interrupting the flow of the material. This provides the advantage of instant feedback and the ability to quickly adjust the process if deviations are detected.
- Online: Similar to in-line sampling, online sampling and analysis takes place while the process is running, but samples are usually taken from the process stream and transported to an analyzer located in close proximity. Online analyses can be carried out continuously or at set intervals.
- Atline: Atline sampling and analysis refers to situations in which samples are taken from the process and taken to an analyzer that is not located directly at the processor but is still nearby (e.g., in a laboratory within the manufacturing facility). Atline analyses are usually performed at regular intervals and not continuously.
- Offline: Offline sampling and analysis involves taking samples from the process and transporting them to a remote laboratory where they are analyzed. This may take some time, and the results are therefore not immediately available to influence the process. However, offline analyses can often provide more detail and accuracy because they can be performed in a controlled laboratory environment.
Choosing the right approach depends on several factors, including the type of material, sampling and analysis requirements, cost, and available infrastructure. Typically, modern processes use combinations of these approaches to achieve an optimal balance between immediacy, accuracy, and cost.