This book is a Monograph, a collection of a few scholarly articles of original research work adopted from author's 1st part of the doctoral dissertation related to development of Low Cost Sensing Technology of Industrial Process variables with simple design and easily available material. The Chapter-1 enriched with brief review of R&D of various workers is a comprehensive appraisal of various process sensors & transmitter in the field of liquid level, Flow, pressure and temperature measurement. The Chapter-2 is composed of all scholarly articles regarding theory of developed sensing technique, design and fabrication of the sensor, experimental evaluation of the performance of the developed sensor with experimental data. Finally, the author describes the contribution of the research output, pros and cons of the development and possibility of future direction of work for each research item as mentioned in this book.The graduate and post graduate university students and research workers studying in this field will get benefit from this book by sharing knowledge in developing low cost sensing technique of industrial process variables.