Method and transit time tester for monitoring the transit time of small-sized goods to be conveyed, particularly of letters and similar mail items

A method for monitoring the transit time of a small-size mail item to be conveyed, comprising:

• providing a transit time tester with dimensions and characteristics substantially corresponding to the small-size mail item to be conveyed and monitored, the transit time tester comprising:
• sensors for providing sensor data related to transportation and processing processes wherein several types of conveyances are utilized for transporting the small-size mail item as part of a sequence of transportation,
• a satellite-based positioning system having a receiver for receiving satellite signals through a satellite link,
• a storage media, and
• a microprocessor for determining from the sensor data a current type of conveyance;
• initializing the transit time tester, the initializing includes storing in the storage data media a plurality of geographic coordinates of a plurality of postal mail centers such that each of the plurality of geographic coordinates corresponds to one of the plurality of postal mail centers, each of the postal mail centers comprising a postal mail sorting machine;
• storing movements of the small-size mail item for later evaluation of the sequence of transportation, the movements stored in the storage media;
• selectively switching the receiver for the satellite-based positioning system on and off as a function of changing conditions of reception of the satellite signals and/or a current type of conveyance utilized for transporting the small-size mail item, the switching the receiver off creating an interruption of the satellite link
• detecting by the transit time tester of a machine pass in the postal mail sorting machine of one of the plurality of postal mail centers;
• and
• after the interruption of the satellite link:
• calculating a current position from data which was stored in the storage media prior to the interruption of the satellite link.