Gill oil level sensors are designed to measure oil level in real-time.
With a solid-state design they require no special maintenance procedures as they contain no moving parts.  

Each and every oil level sensor can be used straight from the box, safe in the knowledge that it has been professionally calibrated to give accurate measurement from the factory, and can be further calibrated to work in specific oils by customer request. With a capacity to store multiple oil calibrations in each sensor, the range offers performance and flexibility to the user.