Sensor and data logger (IMAGE) Purdue University Caption From beneath a concrete pour, this black circular sensor transmits data about the concrete’s strength levels through a cord plugged into an above-ground handheld device called a data logger. Engineers receive real-time data from this device through a smartphone app. Credit Purdue University photo/Rebecca McElhoe Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.