The VA-DTL51H digital datalogger, or thermo-hygrometer, is capable of measuring and displaying temperature and humidity. It is small enough to be portable or handheld. The thermo-hygrometer components record the measurement through mapping, as well as changes in electrical resistance, and continuously displays the measurements on a display unit. Applications include environmental studies, food distribution and installation of heating and cooling systems. It has the ability to store data for 32,000 continuous records, and protect them in the event of a power failure.