HM-40 ThermoHygrometer Spec Sheet All Accessories Phoenix HM-40 ThermoHygrometer With Probe Fast, Accurate, Dependable The HM40 ThermoHygrometer is Vaisala’s newest technology meter with multiple displayed values and real-time acclimation screen for accurate readings. The HM40 displays temperature, RH%, dew point, wet bulb temperature, grains per pound, and BTUs per pound. This compact, portable, easy-to-use humidity meter is the ideal spot-checking tool for fast, accurate and reliable measurements anywhere, anytime. Accurately analyzing the conditions in the affected space is crucial to successful drying. The precision of the HM40 is a must in any restorer’s tool box. Simple and Easy to Use The HM40 includes a user-friendly, large graphical display and easy-to-use push buttons. The user interface is simple and intuitive to use, and available in 10 languages. Also, many other settings can be modified by the restorer to best suit his or her individual needs. In addition to relative humidity and temperature, the HM40 provides five calculated humidity parameters, available in both metric and nonmetric units. The HM40 Humidity Meter is available in both the standard version (4034285) or remote probe version (4034345) . The graph clearly indicates when the readings have stabilized. The meter is powered by 2 AA-sized batteries. An external NiMH battery recharger with USB connection and rechargeable NiMH batteries are offered as an option. Each HM40 comes also with a handy belt clip and a case.