The Extech 45158 is a waterproof, pocket-sized mini thermo-anemometer designed for professionals who need reliable air velocity, temperature, humidity, and dew point measurements in a compact, portable format. Its rugged, water-resistant housing floats if accidentally dropped in water, and the foldable probe extends to 9 inches for easy access into ducts, vents, and hard-to-reach spaces.

The large 9999-count LCD simultaneously displays air velocity alongside one selectable secondary parameter—relative humidity, dew point, temperature, or wind chill—providing comprehensive environmental data at a glance. Air velocity is measured from 100 to 5500 ft/min with ±3% reading accuracy, while temperature is measured from 0 to 122°F (±1.8°F) and humidity from 10 to 95% RH (±4%). Dew point is calculated with ±2% accuracy.

Field versatility is enhanced by a selectable averaging function (5, 10, or 13 seconds) to smooth fluctuating readings, Data Hold to freeze the display, and a tripod mount for hands-free operation. Auto power off conserves battery life during extended use.

Typical applications include:

• HVAC system balancing and troubleshooting
• Indoor air quality assessments
• Ventilation and exhaust testing
• Environmental monitoring and field inspections

Features

• Measures air velocity, temperature, humidity, and dew point
• Air velocity range: 100 to 5500 ft/min (±3% accuracy)
• Temperature range: 0 to 122°F (±1.8°F)
• Humidity range: 10 to 95% RH (±4%)
• Dew point range: 32 to 122°F (±2%)
• Simultaneous display of air velocity and secondary parameter
• Foldable probe extends to 9 inches (229 mm)
• Selectable averaging: 5, 10, or 13 seconds
• Data Hold, Auto Power Off, tripod mount
• Water-resistant housing floats
• 9999 count LCD display