This directory contains the csv files corresponding to the co-location field tests performed at three reference stations of the air quality network of the Madrid City Council, aiming to validate a new hyperlocal IoT particle matter device that integrates an innovative dryer to correct the error due to the hygroscopic growth in high relative humidity conditions. In concrete, three devices have been deployed in the Escuelas Aguirre, Cuatro Caminos and Mobile Unit during July/August 2021. Each csv has the following columns: - date: date of measurement - PM10_Reference: PM10 concentration according to reference station - PM2.5_Reference: PM2.5 concentration according to reference station - PM1_Reference: PM1 concentration according to reference station - TIME: date in currentmillis - PM1: PM1 concentration according to hyperlocal IoT device - PM2.5: PM2.5 concentration according to hyperlocal IoT device - PM10: PM10 concentration according to hyperlocal IoT device - TEMEPERATURE_INT: temperature inside the hyperlocal IoT device - HUMIDITY_INT: humidity inside the hyperlocal IoT device - TEMEPERATURE_AMB: ambient temperature - HUMIDITY_AMB: ambient humidity