Electro-Sensors, Inc. began operations in 1968 in St. Louis Park, Minnesota. It was founded by James P. Slattery to serve material handling and process control applications in industrial plants. The original products included the Bin-Levetrol level sensor which sensed presence or absence of material and functioned as a high or low level control for bins or hoppers used in dry bulk material handling systems. Another core product was a speed monitor for monitoring critical shaft speeds and was used on conveyor belts, screw conveyors, bucket elevators, and similar process equipment. This speed monitor would shut off the driven equipment if proper speed was not maintained. As the company grew,