ISR-400 is a precision indoor air meter, and it can view measurement mode and graph mode in real time by 6.4 inch large color TFT-LCD. It is a high performance meter that can conveniently operate the conversation type menu buttons by touch screen. Having a large volume memory embedded, ISR-400 has the function, as a data logger, to store the measurement data of more than 100,000 points and is an intelligent analyzer to search and analyze the stored data directly by LCD without being connected to a separate computer. Having a small embedded printer that can print the measured data directly in the field, it is appropriate for field printing. In addition, measured data can be stored through direct backup. It is a portable analyzer that can be moved conveniently.