By password-protecting calibration, Model DL200-T protects integrity of acquired data. Device measures -40 to +85°C with 0.5°C accuracy; up to 2,048 time/date stamp readings can be logged at any whole-minute interval from 1 min to 4 hr. Green LED shines when measurements fall inside preset limits; red LED shines when they do not. Bundled Windows-based software lists or graphs data. Lithium battery powers unit for 3 yr.