GSM datalogger is designed to record temperature and humidity from built-in sensors. In case of exceeded set limits, SMS and JSON messages can be sent via GPRS data connection. It is possible to set the regular sending of JSON messages to COMET Database, the sending interval is adjustable. Alarms are also indicated locally by LED, LCD and acoustically by built-in beeper. The recording is performed in a non-volatile electronic memory. The data can be transferred to a PC via USB-C. GSM recorder includes Traceable calibration certificate with declared metrological traceability of etalons is based on requirements of EN ISO/IEC 17025 standard.