Fully printed microwave sensor for simultaneous and independent level measurements of 8 liquids

Level sensors find numerous applications in many industries to automate the processes involving chemicals. Currently, some commercial ultrasound, capacitance and microwave radar based level sensors are being used for medical and industrial usage [1]. Some of the desirable features in any level sensor are its non-intrusiveness, low cost and consistent performance. It is a common stereotype to consider microwaves sensing mechanism as being expensive. Unlike usual expensive, intrusive and bulky microwave methods of level sensing using guided radars, this paper presents an extremely low cost, fully printed, non-intrusive microwave sensor to reliably sense the level/volume of 8 different types of liquid independently and simultaneously. This paper presents a new microwave level sensor whose design is inspired by a T-reso-nator. A unique modification of the conventional T-resonator enables it to sense liquid level/volume present inside any metallic container of cylindrical shape. The proposed sensor can be thoroughly fabricated using additive manufacturing like 3D and screen printing making it easier, faster and cheaper to realize.