The MT669 is a temperature and humidity data logger designed with a high accuracy temperature and humidity sensor. This data logger provides fast response and stability. This logger gives clear readings on the large LCD display and the user can check at a quick glance the actual time of the minimum or maximum reading for temperature and humidity. The MT669 has a selectable measuring time intervals from 1 seconds to 24 hours and can store up to 16,350 readings for both temperature and humidity. The user can define the upper and lower measurement parameters for temperature and humidity and if these readings go above or below these parameters, the alarm LED will flash.