The temperature data logger is a device to read temperature and store persistent temperature and corresponding timestamp data into Flash memory. The collection of temperature data can be retrieved, and analyzed after being logged. The temperature data logger is commonly used for monitoring environmental data and shipments of temperature sensitive products such as foods, pharmaceuticals, and some chemicals. In particular, temperature data logger can operate as a stand-alone device and put in a variety of locations including office, laboratory or geographical location such as mountains, deserts,… and in manufacturing line in industry to collect temperature data over a defined period of time. It is also small enough and portable to be integrated with shipping container or directly attached to products which can be degraded due to exposure to temperature extremes to monitor their temperature. -The temperature data logger is a device to read temperature and store persistent temperature and corresponding timestamp data into Flash memory. The collection of temperature data can be retrieved,　and analyzed after being logged. The temperature data logger is commonly used for monitoring environmental data and shipments of temperature sensitive products such as foods, pharmaceuticals, and some chemicals. In particular, temperature data logger can operate as a stand-alone device and put in a variety of locations including office, laboratory or geographical location such as　mountains, deserts,… and in manufacturing line in industry to collect temperature data over a defined period of time. It is also small enough and portable to be integrated with shipping container or directly attached to products which can be degraded due to exposure to temperature extremes to monitor their temperature.