Testo 175 H1 Temperature & Humidity LoggerThe Testo 175H1 is a compact professional data logger for monitoring Temperature, Humidity & Dew Point. The external temperature & humidity probe creates faster reaction times compared to other temperature & humidity data loggers available in the market. The 175 H1 data logger measures, monitors, and logs the temperature and relative humidity in buildings and closed rooms. The logger has an external humidity sensor (stub) for shorter reaction times