Testo 425 Compact Digital Hot-Wire Anemometer, 0 to 20 m/s Velocity, -20 to +70° C Temperature

The Testo 425 anemometer with telescoping hot-wire probe reaches into tight spaces to measure air velocity in m/s and fpm, air flow volume in m3/h and cfm, and air temperature in degrees C and F; and has hold, maximum, minimum, and mean functions for analyzing air flow. Hold function freezes a reading on the display to aid documentation, and the maximum and minimum functions display highest and lowest readings since the meter was powered on or reset. Mean function displays the multi-point average of recorded readings as well as the average reading during a timed measurement. The meter includes a calibration certificate. The LCD shows two parameters simultaneously and a backlight provides visibility in low light. The unit has an auto-off mode that shuts it down after 10 minutes of non-use to conserve battery life and has a low-battery indicator. This anemometer is used for monitoring air flow and temperature in ductwork, spray booths, and exhaust hoods, among other applications.

Specifications

H is height, the vertical distance from the lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.

Anemometers, also called wind meters, measure air velocity and are most commonly used for weather monitoring to determine wind speed and for HVAC applications to determine air flow within ducts. In addition to air velocity, anemometers may measure wind direction, air pressure, air flow volume, air temperature, humidity, light, and other properties. The most common types of anemometer are cup, vane, hot-wire, and Pitot tube. Cup and vane anemometers calculate air velocity based on the number of rotations of the cups or vane. Hot-wire anemometers calculate air velocity by measuring the change in electrical resistance as air flow cools a heated wire. Pitot tube anemometers measure air pressure within a tube and calculate air velocity based on the difference in pressure between the air inside and outside of the tube. Many anemometers have digital readouts and can display air velocity readings in different units of measure, such as meters per second (m/s), feet per minute (ft./min. or fpm), knots, miles per hour (mph), and kilometers per hour (km/h).

Testo manufactures portable test and measurement instruments. The company, founded in 1957 in Germany, has a U.S. office in Sparta, NJ, and meets International Organization for Standardization (ISO) standard 9001.

What's in the Box?

• Testo 425 anemometer with hot-wire probe
• (1) 9V battery
• Calibration certificate