New issue of our bulletin The compressed air economy is in the world! We are pleased with your great interest and positive feedback, and have been asking you for a long time after the next issue, we have picked it up today in the printer. The main topic is this time focused on the quality of compressed air, presenting individual quality classes and problems of compressed air treatment. The main theme is followed by an example of practice concerning the certification of compressed air quality for the food industry. Here are some examples of the analyzes performed, such as the costing of a nitrogen generator, the use of the Atlas Copco ES control system, the cost comparison of pressed and welded pipes and much more. You will also learn about the course of research we are involved with VŠB Ostrava. We wish pleasant reading.