Extech 407123 Anemometer / Air Flow – Type (anemometer): Hot-Wire, Measurement (anemometer): Ft/Min, Air Velocity Max: 3940 ft/min

Extech 407123 Heavy Duty Hot Wire Thermo-Anemometer.

Hot Wire Thermo-Anemometer
This Heavy Duty Hot Wire Thermo-Anemometer uses a telescoping probe (extends up to four feet) with a 0.5 inch diameter sensor that’s ideal for use in ducts and ventilating systems.
Applications

• HVAC installation, repair, diagnostics, and optimization
• Positive pressure tests in clean rooms
• Fume hood testing, installation, and verification
• Automobile engines analysis, passenger compartment tests, and aerodynamic testing
• Ionizer flow output monitoring
• Ventilation system installation, servicing, and analysis
• Environmental wind and temperature testing/analysis
• Boiler rooms
• Plant/Facilities Maintenance.

How Does An Anemometer Measure Moving Air?
Anemometers measure moving air with a rotary sensor that acts very much like a weathervane and can be likened to the blades of a fan. The vane freely rotates in response to airflow, and as the air moves through the vane the blades turn in proportion to the speed of the air.

What Is CFM / CMM?
Cubic Feet per Minute (CFM) or Cubic Meters per Minute (CMM) are units of measure for air volume measurements. This is a measurement of the quantity of moving air through an air duct, passageway, or enclosure. In order to determine this, the area of the duct must be measured. The area value (in ft2 or m2) is entered by the user, by pushbutton or keypad into the meter and an air velocity is determined.

What Is The Difference Between Vane And Hot-Wire Anemometers?
Vane Anemometers use a remote fan (vane) that freely rotates in response to air flow. The vane movement equates to air velocity readings that can be displayed on a meter. The Hot Wire Anemometer sensor is a special wire whose resistance fluctuations are translated into air velocity readings that can be displayed on a meter.

Which Applications Are Best For Vane And Hot-Wire Types?
Hot-Wire Anemometers offer a slim sensor (0.5″ diameter), well suited for accessing small openings and crevices (engine compartments and small ventilating systems). Hot-Wire Anemometers don’t have vulnerable, movable mechanical parts that can wear or become damaged over time. Vane Anemometers are lower cost and allow easy visual inspection of the moving vane (great for air duct and fume hood applications).