The Triplett GSM350 Carbon Monoxide/Carbon Dioxide IAQ Datalogger simultaneously displays CO, CO2, Temperature, and Humidity on its large color display with 4 brightness levels. It can be used to measure air quality in office buildings, schools, exhibition halls, shopping malls, meeting rooms, fitness centers, restaurants and other public places. It has a user settable datalogging duration period of 1 hour, 24 hours, or 7 days, with a sampling rate of 1 minute, 15 minutes, or 1 hour. Captured readings can be viewed in a Histogram on the display or users can transfer historical data to the PC in Excel (CSV) format via USB. Additional features include audible CO and CO2 alarms with user adjustable settings, real time clock, Min/Max/Average to record the highest, lowest and average readings, Data Hold freezes the reading on the display, and Auto power off with disable to conserve battery life; °F/°C are selectable.