Data Logger Systems are rapidly taking the place of chart recorders for recording temperature. These devices electronically store data associated with the dates and times the data is acquired. Dataloggers can be programmed for sampling intervals from seconds to hours for any length of time the operator requires. The data logger can be connected to a computer or it can stand alone in a remote location and the data points downloaded periodically. One application would be monitoring a refrigerator or freezer over the weekend. A simple memory digital thermometer only remembers the highest and lowest temperature achieved during a time interval but not how long the refrigerator was at that temperature or exactly when. Alternately a thermometer with outputs for a data logger can assign a specific date and time to the high and low temperatures. A data-logger is connected to the thermometer on Friday night and on Monday morning the data is downloaded to a computer. In this way the laboratory or clinic would know the conditions inside the refrigerator for the entire weekend. Data loggers are used in shipments of pharmaceuticals and biological samples with sensitive temperature requirements to verify that the environment was never at a temperature which would degrade the samples. Data loggers are also used to monitor weather at remote locations. Data for temperature, humidity, wind speed, and barometric pressure at specified sampling intervals, e.g., every hour, can be stored over extended periods of time. The data can be downloaded periodically or monitored with a remote computer on site.