Abstract: A time temperature recording device especially adapted to the business of transporting perishables and characterized by a preloaded returnable instrument of permanent nature packaged in a protective liner held secure and warranted by a sealed box that is expendible, with separate access openings for exclusive use of shipper and receiver respectively, and wherein a logic means permits depression of a stylus onto a pressure sensitive chart when instrument operation is started by the shipper, and lifts said stylus and releases said chart when stopped by the receiver. The used instrument is especially adapted to be returned by the Postal Service.