The Purity of Working Liquids and Oils . Determination of the working fluid purity class” by A. and . Verenia is an important and relevant publication that will become an indispensable assistant for specialists in the field of mechanical engineering, chemical technology and lubricants .. In today's production environment, where the quality and reliability of equipment play a key role, understanding the purity of working fluids and oils becomes necessary to ensure the efficient operation of machines and mechanisms. In his book, Verenich examines in detail the methods of determining the class of purity of working fluids, which allows the reader not only to understand how to correctly assess the quality of oils and liquids, but also to identify potential problems associated with pollution. The author shares his knowledge and experience, offering practical recommendations and scientific justifications, which makes the material accessible and understandable even for those who are just starting their way in this field. The book will be of particular interest to engineers, technologists, as well as students of technical universities studying disciplines related to materials and their properties. It is suitable for both professionals who want to deepen their knowledge, and for beginners who want to understand the complex but fascinating topic of purity of liquids. If you work in the field of machine maintenance and repair, or are engaged in the development of new technologies, this publication will become a real guide for you. The topics raised in the book cover a wide range of issues: from the basics of determining the purity of liquids to the analysis of the impact of pollution on the operation of equipment. Verenich emphasizes the importance of quality control of working fluids, emphasizing that even small impurities can lead to serious breakdowns and increase maintenance costs. In this context, the book becomes not just a textbook, but a real manual for improving production efficiency. The style of the author is clear and logical, which makes it easy to assimilate even the most complex concepts. Verenich is known for his scientific works and publications in the field of materials science and technology, and in this book he continues his tradition of sharing knowledge with readers. His approach to the presentation of the material is based on a combination of theory and practice, which makes the book useful for both theorists and practitioners. If you are looking for information about the purity of liquids, methods of their analysis, as well as practical recommendations for improving the quality of working fluids and oils, this publication will be a real find for you. The Purity of Working Liquids and Oils . Defining the Working Liquid Cleanliness Class is not just a collection of facts, but an in-depth study that will help you better understand the importance of cleanliness in production processes. Do not miss the opportunity to expand your knowledge and improve your skills with this unique work Verenich’s book is not only a useful resource, but also a source of inspiration for all who strive for perfection in their professional activities.