Sensors with Digital Output – A Metrological Challenge

Abstract

The Internet of Things (IoT) as well as many other new applications require sensors that can already process data inside the sensor and exchange the pre-processed data more or less directly with their environment. Such sensors typically have a digital output and thus challenge current calibration systems which usually have analogue input channels. Furthermore most calibration standards were written for an analogue world and do not fit to sensors with internal A/D converters and data pre-processing. Based on experiences of the authors with the calibration of accelerometers with digital output, the paper will give an overview over the challenges that we will face in a digital sensor world. How will calibration systems for such transducers will look like? How do I calculate a measurement uncertainty if the signal processing inside a sensor is a black box? The paper addresses the challenges and tries to give an outlook how to meet them.