Alnor AVM440 Velometer Thermal Anemometer with Humidity Measurement is an accurate digital air velocity meter and humidity meter that is like having multiple meters all in one. Alnor AVM440 measures temperature, velocity, humidity, wet bulb, dew point and volumetric flow which makes it a great choice for HVAC troubleshooting and commissioning work. This model includes an articulated probe. Made in the USA and includes a NIST Calibration Certificate.