Docooler USB Humidity Temperature Data Logger Recorder LCD Display LED Alarm D Graph Portable, precise, compact and low cost. USB interface directly communicate with PC for setup and data download. Unique and uniform PC control software: DGraph. Able to customize the unit, supporting user-defined data curve output. Able to customize compound graph from selected logging data by inputting formula. Able to name each channel and enable/disable specified channel freely. Able to analyze the dew point data through software. Able to enter a password to set data download limit. Able to setup sample rate (from 10 seconds to 12 hours). Each logger has a unique serial number, data of more loggers can be compared and analyzed on the same curve interface. All data from different data logger and all different measurement parameters can be graphed and analyzed together. Three way to start logging: immediately, start by button, start at date & time. User can input two point calibration value for each channel when setup. Logger can be used as a portable measuring instrument when in non-recording mode. With LCD screen for viewing real-time data easily. Logger status, alarm indication and low battery indication via LED light. USB interface, directly connected with PC for setup and data download. Replaceable lithium battery and data is not lost if exhausted.