Capacitive liquid level sensing method comparison discussed in this app note from Texas Instruments. Link here (PDF)
Capacitive-based liquid level sensing is making its way into the consumer, industrial, and automotive markets due to its system sensitivity, flexibility, and low cost. With using TI’s capacitive sensing technology, the system flexibility allows designers to have the choice of placing the sensors directly on the container (direct sensing) or in close proximity to the container (remote sensing). Each configuration has its own advantages and disadvantages. This application note highlights the system differences and performance of direct and remote sensing to provide guidance in how capacitive-based liquid-level sensing is affected.
App note from Infineon on methods used in liquid level measurement and how contactless hall effect sensors are the right choice for the job. Link here (PDF)
This application note is dedicated to liquid level sensing using non-contacting magnetic sensor technology. First, an overview of some liquid level sensor application requirements are given. Next, we will introduce some of the solutions that are employed today and are researched for future systems, including both contacting techniques as well as non-contacting methods. Magnetic sensing turns out to be a comparably easy and robust solution to tackle the problem and Infineon’s linear Hall sensor portfolio is presented. Different design aspects of a magnetic liquid level sensor, including magnetic circuit designs, are discussed. The last section introduces some of Infineon’s Hall effect sensors that are suitable for use in fuel level sensing.