# An Introduction to Anemometers

## An Introduction to Anemometers

### Alternate Terms for Anemometers

• Air Flow Meters
• Air Velocity or Wind-speed Meters
• Wind cups or weathervanes

### What is an Anemometer?

Anemometers measure the speed (velocity) of moving air. Thermo-Anemometers also measure temperature by way of a thermometer located in the Anemometer sensor. The measurement units for Anemometers include: Feet per minute (ft/min), meters per second

(m/s), kilometers per hour (km/hr), miles per hour (mph), nautical miles per hour (knots), and Beauforts.

### How does an Anemometer measure moving air?

Anemometers measure moving air with a rotary sensor which acts very much like a weathervane and can be likened to the blades of a fan. The vane freely rotates in response to air flow 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 accomplish this, the area of the duct must be measured. The area value (in ft2 or m2) is entered by the user by push button or keypad into the meter and an air velocity measurement is taken. The meter then calculates the CFM or CMM automatically.

### What is the significance of a built-in IR thermometer?

Having an IR thermometer as part of an Anemometer offers the user several important benefits:

• Two tools in one
• Save time and cost
• Check for hot spots in duct work, electrical panels, and wiring conduits

### Typical Anemometer Applications

• Air duct measurements
• Positive pressure tests in clean rooms
• Fume hood testing and verification
• Automobile engines analysis
• Automobile passenger compartment tests
• Ionizer flow output monitoring
• Ventilation system inspection

Source: Extech Instruments