Portable efficiency measurement system for HVAC and related work, with hot wire anemometer, static and differential pressure, temperature and humidity measurement with heat flow efficiency calculation. Velocity (hot wire) 0 to 50m/s, accuracy +/-3%. Temperature -10 to 60 degree C, accuracy +/-0.3. Wet bulb temperature 5 to 60 degree C. Relative humidity 0 to 95%RH, accuracy +/-3%. Dewpoint -15 to 49 degree C. Static/differential pressure -3,735 to 3,735Pa, accuracy +/-1%. Probe length 1m, tip diameter 7mm, base diameter 10mm. Includes data logging and printing. Battery operated. USB & Bluetooth download.