A method of operating a datalogger adapted for logging sensor data from an absorbent article having at least one sensor element and the datalogger are described. The method includes: determining an external event and on determination of the external event, transitioning from a first operating condition to a second operating condition. The external event can be an event selected from: a disconnection event in which the datalogger is disconnected from the absorbent article a connection event in which the datalogger is connected to an absorbent article a charge event in which the datalogger is connected to a charging station and a user interaction event in which the user interacts with a user interface element of the datalogger. The first and second operation conditions can be selected from: a datalogging condition a standby condition a status notification condition and a data transmission condition.
