Ld 9121 series temperature and humidity data logger has internal high-precision sensors for temperature or temperature and humidity measurements. There is no need to install any software to automatically generate a pdf report. The device stores maximum 16000 measuring data automatically with selectable sampling intervals from 1s to 24h. It is equipped with intelligent data analysis and management software for data download, graph checking and analysis, etc. This device is designed with lcd, led indicators and buttons. Real-time readings and alarm information can be displayed on lcd. The two leds flash in red, green and yellow colors to indicate the status of working and alarming. Its easy to operate with the two buttons to check data, start logging and clear data.