The Dwyer 8904 integral vane thermo-anemometer is a compact, versatile instrument designed for simultaneous measurement of air velocity and temperature in HVAC, energy management, and ventilation applications. Its large 1.3‑inch LCD display provides clear visibility of readings, while user‑selectable wind speed units (ft/min, m/s, knots, mph, km/h) accommodate diverse measurement requirements.

The meter features a 2‑7/8‑inch integral vane with fast 1‑second response for air velocity from 80 to 5900 ft/min, accurate to ±3% of reading. A built‑in temperature sensor measures ambient conditions from 14 to 122°F with ±1°F accuracy. For detailed analysis, the 8904 records minimum, maximum, and average readings at a single point, and can average data over up to two hours while continuously displaying the running average—ideal for duct traverses and long‑term monitoring.

An RS‑232 interface enables connection to PCs or data loggers for remote data acquisition (cable/software sold separately). Additional features include Data Hold, 100‑hour battery life from a standard 9V cell, and CE approval. The rugged, portable design makes the 8904 a reliable choice for field professionals.

Typical applications include:

• HVAC system balancing and commissioning
• Energy audits and building performance analysis
• Ventilation system verification
• Industrial hygiene and indoor air quality assessments

Features

• Simultaneous air velocity and temperature measurement
• Air velocity range: 80 to 5900 ft/min (0.4 to 30 m/s)
• Temperature range: 14 to 122°F (-10 to 50°C)
• ±3% air velocity accuracy, ±1°F temperature accuracy
• Selectable velocity units: ft/min, m/s, knots, mph, km/h
• Data Hold, Min/Max/Average recording
• 2‑hour data averaging with continuous running average display
• RS‑232 serial interface
• Large 1.3" LCD display
• 2‑7/8" integral vane with 1‑second response
• Powered by 9V battery (100‑hour life), CE approved