The Dwyer 471B thermo anemometer with hot-wire probe reaches into ducts to measure air velocity in m/s and fpm and air temperature in degrees C and F; calculates air flow volume; and has memory, maximum, minimum, average, and hold functions for analyzing air flow. The probe attaches to the meter body with a coiled cable that extends from 71 to 183 cm (28" to 6 ft.). Memory function stores and recalls up to 99 readings. Maximum and minimum functions display the highest and lowest recorded readings. Average function records readings over 10, 30, or 60 seconds and displays the average value. Hold function freezes a reading on the display to aid documentation. An integral cover slides over the head of the probe to protect the velocity and temperature sensors when not in use. The meter has a 4.5-digit LCD for viewing readings with a backlight for visibility in low light. The unit has an auto-off mode that can be programmed to power down after 10 or 30 minutes of non-use to conserve battery life and has a low-battery indicator. It has European Conformity (CE) marking. This anemometer is used for monitoring air flow and temperature in ductwork, spray booths, and exhaust hoods, among other applications.
|Air velocity range||0 to 30 m/s; 0 to 6,000 fpm|
|Air velocity resolution||0.1%|
|Air velocity accuracy||+ or - 3% of full scale at temperatures from 4 to 32 degrees C/40 to 90 degrees F|
|Air flow volume range||To 19,999 in selected flow units|
|Air temperature range||-40 to +100 degrees C/-40 to +212 degrees F|
|Operating environment||-15 to +51 degrees C/5 to 125 degrees F|
|Power||(1) 9V battery (included)|
|Probe length||203 mm/8"|
|Weight||454 g/16 oz.|
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).
Dwyer Instruments manufactures measurement and control instruments, including pressure gauges, flow meters, level instrumentation, temperature instrumentation, and air quality monitors. The company, founded in 1931, is headquartered in Michigan City, IN.