The GSM-2 data logger from Keller is used to conveniently track pressure measurements such as filling and water levels remotely and to monitor limit values. The device has since been further developed and has been given a new name: Autonomous Remote Data Collector, or ARC-1 for short. For compatibility reasons, the new model includes the same functions as the old one. What is new is that it communicates via the 3G mobile radio system, optionally also via 4G. The new radio modules also allow localization via the mobile network. In addition, the mini SIM card has been replaced by a micro SIM card. On request, the data logger can also be supplied with an e-SIM. A humidity sensor has also been added to the system status information, such as battery status and signal strength. A real-time clock (RTC) integrated in the data logger continues to run independently when the battery is changed. In addition, existing GSM-2 data loggers can easily be upgraded to ARC-1 data loggers if the 2G network is no longer available at the existing measuring point. The Kolibri Cloud API allows customer-specific software to retrieve measured values via HTTPS in a standardized JSON format.